Speaker 1: Welcome to tech Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host
Speaker 1: Jonathan Strickland, Diamond executive producer with iHeart Radio and how
Speaker 1: the tech are you? It's time for a tech Stuff
Speaker 1: classic episode. This episode is called d n A Forensics.
Speaker 1: It originally published on October seventh, two thousand fifteen. In
Speaker 1: this episode, Ben Bolan, host of such shows as Ridiculous
Speaker 1: History as well as Stuff they Don't want you to
Speaker 1: know and as a tireless producer, the kind of person
Speaker 1: you can ask to be on your show and he'll
Speaker 1: say yes, even if he's already committed to like a
Speaker 1: billion other things, and he'll somehow find a way to
Speaker 1: do all of them. I don't understand this man anyway.
Speaker 1: He joined the show to talk about DNA forensics. Hope
Speaker 1: you enjoy this classic episode. Ben has had people mark
Speaker 1: all over him and crayon today. I'm not gonna ask
Speaker 1: why I don't get into personal lives in the show. Well,
Speaker 1: you know, it's it's a big deal. Whenever I could
Speaker 1: be on the show and I wanted to do something special,
Speaker 1: my suits at the cleaners got a bunch of sharpies
Speaker 1: and asked people to go nuts. It's kind of like
Speaker 1: body paint, but really they'll super like on the cheap
Speaker 1: because we just can't. We don't have that in our budget, honestly, right,
Speaker 1: not yet. But Hope springs eternal. And what's weird about
Speaker 1: having um all these all these colors and markers all
Speaker 1: over me is that anything I touched literally is leaving
Speaker 1: a trace. Yeah, and that kind of you know, we
Speaker 1: were going to have a really in depth conversation on
Speaker 1: how catalytic converters work, but once I noticed you're doing that,
Speaker 1: I thought, why don't we talk about DNA forensics, like
Speaker 1: the traces people leave behind. So that's why I decided
Speaker 1: to switch in the last minute. I hope you can
Speaker 1: roll with it. Oh yeah, yeah, yeah yeah. And just
Speaker 1: in in you know, Ben and I have talked a
Speaker 1: little bit about our our mutual interest in the true
Speaker 1: crime uh discipline, the whole the whole true crime like field,
Speaker 1: and it turns out we're not the only ones in
Speaker 1: the office. There are certain people in the office who
Speaker 1: have a really deep interest in this sort of stuff,
Speaker 1: and so we thought, you know, it'd be kind of
Speaker 1: fun to explore the concept in different shows. So if
Speaker 1: you listen to all of How Stuff Work shows, you
Speaker 1: may have noticed things popping up here and there that's
Speaker 1: not entirely by accident, and so, uh really was one
Speaker 1: of those things where as we all started talking, we're like, hey,
Speaker 1: you know, I would like to do something in that
Speaker 1: and we can kind of It's almost like an easter
Speaker 1: egg for those of you who subscribe to lots of
Speaker 1: different shows, and you should let us know if you
Speaker 1: thought it was really cool. So from the technology standpoint,
Speaker 1: we thought DNA forensics would be really really interesting to
Speaker 1: cover and to talk about how it actually works. Uh,
Speaker 1: what are the processes, what are some of the challenges,
Speaker 1: What are some of the things that people are doing
Speaker 1: with DNA forensics now that might end up helping uh,
Speaker 1: like investigations in the future where could it actually end
Speaker 1: up giving us a false positive, because there there is
Speaker 1: the possibility of that as well. But to start it
Speaker 1: all off, we really kind of have to lay the groundwork. Yeah,
Speaker 1: I was gonna I was just gonna ask you. I
Speaker 1: hate to be the bad kid in class right now,
Speaker 1: but what's what's DNA d oxy ribonucleic acid, man, Yeah,
Speaker 1: that's that's what it is. It's so obviously you know,
Speaker 1: anyone who's had science class, like a biology class anything recently,
Speaker 1: you know all about DNA. But you know, we gotta
Speaker 1: build from the ground up. So DNA is a molecule
Speaker 1: that carries the genetic instructions that govern the development, function,
Speaker 1: and reproduction of organisms. DNA is found in all of
Speaker 1: your cells. Essentially, an entire blueprint of what makes you
Speaker 1: you is in every single one of your cells in
Speaker 1: the form of d N A UH. And the molecule
Speaker 1: is in that double helix form. So that says, if
Speaker 1: you were to make a ladder and then twisted in
Speaker 1: to a twisty shape, that's the DNA double helix. The
Speaker 1: rungs on that letter are made up of pairs of
Speaker 1: what we call nucleotides, alright, So each rung on the
Speaker 1: ladder is two different nucleotides that that bond together. Uh.
Speaker 1: There's adenine and thymine. Those always pair up together. So
Speaker 1: those are your two base pairs of nucleotides that will
Speaker 1: always join. And then there's guanine and cytosine and those
Speaker 1: always join. And it's the sequence of these pairs that
Speaker 1: end up determining what makes you you. Right yeah, yeah,
Speaker 1: so it could be. And these pairs can affect multiple
Speaker 1: the order of these pairs can affect multiple characteristics. Sure, yeah, absolutely.
Speaker 1: And also what's really interesting to me is that point
Speaker 1: nine of all the DNA that is in you is
Speaker 1: shared with every other human Like we we have ninety
Speaker 1: nine of our DNA in common, which means the stuff
Speaker 1: that makes you who you are as indifferent from every
Speaker 1: other person makes up just point one percent of your DNA.
Speaker 1: But that's all it takes. Is that point one percent.
Speaker 1: That's about three million base pairs that are unique to
Speaker 1: you unless you have an identical sibling. Ah ah the
Speaker 1: old Now this goes into um, this verges into some
Speaker 1: good detective fiction. Now, yes, that old The evil twin, Yeah, exactly,
Speaker 1: it wasn't me. It was my evil twin or or
Speaker 1: evil triplet or evil quadruplet really which we did an
Speaker 1: ill fated brain Stuff but it was, oh my gosh,
Speaker 1: we did. We did. Yeah. If you if you watch
Speaker 1: brain Stuff the video series and you look up how
Speaker 1: twins work, Ben and I did a funny At the time,
Speaker 1: I thought I still thought there were parts of it
Speaker 1: that were funny. Honestly, Ben, I still fully enjoy it,
Speaker 1: but my sense of humor is very corny. So but
Speaker 1: if you want to see you want to see me
Speaker 1: and Ben dressing up in two different types of outfits,
Speaker 1: like we're the the good Ben and Jonathan and then
Speaker 1: there's the evil Ben and Jonathan and we each have
Speaker 1: an eyepatch. Jonathan I were talking and it was it
Speaker 1: was strange because when we were talking about doing this
Speaker 1: episode and said, well, how could we represent evil twins
Speaker 1: like I patch is clearly because you know, the the
Speaker 1: goatee is not gonna work for right, because it wasn't
Speaker 1: like neither of us were going to end up shaving
Speaker 1: just so that I can be the good twin. But
Speaker 1: both of us are the kind of person who would
Speaker 1: have an I patch. And actually I ended up taking
Speaker 1: a quick walk to a nearby toy store to pick
Speaker 1: some up um. So, at any rate, if you do
Speaker 1: have an identical sibling, your identical sibling shares your DNA.
Speaker 1: There they are identical like the d N. If you
Speaker 1: were to compare the two and look at those base pairs,
Speaker 1: they're going to be the same all the way down, right,
Speaker 1: So that's one of the that's one of the exceptions.
Speaker 1: Really the exception so our DNA can be found in
Speaker 1: twenty three pairs of chromosomes. That's what humans have. Not
Speaker 1: all animals have that many, so have fewer, and etcetera, etcetera.
Speaker 1: So chromosomes are ribbons of protein essentially have a strand
Speaker 1: of DNA that are wrapped up in that and within
Speaker 1: each pair, one chromosome comes from your mother, one chromosome
Speaker 1: comes from your father, and that's what uh you know,
Speaker 1: those are the ingredients that come together to create the
Speaker 1: unique individual that is you and or your identical siblings.
Speaker 1: Uh So, if we took look at each person's DNA
Speaker 1: and pay attention to the order of those base pairs,
Speaker 1: we get something like a d NA fingerprint. It is
Speaker 1: unique to that person. But we can't just look at
Speaker 1: one section. We have to look at several different sections
Speaker 1: also known as loci in the in the parlance of
Speaker 1: forensics to get a robust fingerprint profile. So, just as
Speaker 1: we would look at a fingerprint and look for points
Speaker 1: of comparison to from from a from a fingerprint that
Speaker 1: we've gathered from a suspect, let's say, and a fingerprint
Speaker 1: that is left at the scene of a crime, you
Speaker 1: would have to look at several different points to make
Speaker 1: sure that all those points correspond to one another to
Speaker 1: say that there's a match. Same thing with DNA DNA forensics,
Speaker 1: you would look at several different locations along a strand
Speaker 1: of DNA and see if the same sequence of nucleo
Speaker 1: tides were appearing on both sets, because that would tell
Speaker 1: you what are the statistical probabilities of the person that
Speaker 1: you suspect and the the evidence that was left behind
Speaker 1: are one and the same, right, Okay, So each time
Speaker 1: there's a new location, the more loci there are, the
Speaker 1: more certitude you have that you've got your catch. Yeah,
Speaker 1: if you were to say, look at just one location,
Speaker 1: then that would mean you would have a very you know,
Speaker 1: there's actually quite a good chance depending upon the sequence,
Speaker 1: that coincidence could could completely explain away any any uh
Speaker 1: duplication there. Right, So it could just be coincidence. It
Speaker 1: could be that this person just coincidentally has that same sequence.
Speaker 1: As you add more loci, that becomes less and less likely.
Speaker 1: Uh FBI. The FBI has thirteen that they suggest, so
Speaker 1: thirteen specific loca that's their standard, and that that results
Speaker 1: in about a one in a billion chance that if
Speaker 1: you were to take all thirteen loca and compare the
Speaker 1: two strength you know, the stuff that was left at
Speaker 1: the evidence and the suspect or whatever is in the database.
Speaker 1: If you were to compare the two and they were
Speaker 1: to come up equal at all thirteen, it's a one
Speaker 1: in a billion chance that somebody else besides the person
Speaker 1: you're looking at possesses that. So seven of the six
Speaker 1: other people in the world. Yeah, it's like flash forward
Speaker 1: to that day in court where someone's doing that horrible
Speaker 1: reference joke and going, so you're saying that there's a chance. Yeah,
Speaker 1: And honestly, people who are analyzing the stuff they speak
Speaker 1: in statistical probabilities, because you cannot say for certain that
Speaker 1: this person left behind that DNA. You can say, like,
Speaker 1: what is the statistical probability that they did? And then
Speaker 1: you look at other elements of the case, right like saying,
Speaker 1: all right, can we put the person in that area,
Speaker 1: because let's say that it's in a small town. Well,
Speaker 1: if it's a one in a billion chance and you
Speaker 1: know that the suspect was in that small town, that's
Speaker 1: a pretty darn compelling yeah, because why are the chances
Speaker 1: of the other one of the other six people in
Speaker 1: the entire world was also in that small town. Not good,
Speaker 1: Ben and I will be back to talk more about
Speaker 1: DNA forensics after we take this quick commercial break. So
Speaker 1: where do we get the DNA evidence from? Well, stuff
Speaker 1: that people leave behind, Uh, a much anything that has cells,
Speaker 1: like living tissue that was left behind our living or
Speaker 1: stuff where living cells could have been in before being
Speaker 1: deposited at the crime scene. So stuff like blood or
Speaker 1: saliva or semen or skin cells, mucus, ear wax, sweat. Yeah,
Speaker 1: all of that, All of that can leave behind cells
Speaker 1: that we can pull DNA from that. What about hair,
Speaker 1: hair not so much, not not not for traditional DNA
Speaker 1: hair follicles, yes, but hair itself is dead. Those are
Speaker 1: dead cells. So you can do some some DNA analysis,
Speaker 1: but not the the standard kind that most people use
Speaker 1: in DNA. For instance, Uh, fingernails, same thing, but fingernails
Speaker 1: often come with other tissue attached to it, and that's
Speaker 1: where you find the DNA. So if we want to
Speaker 1: look at the history of people actually saying hey, why
Speaker 1: don't we use this this DNA stuff to try and
Speaker 1: help with investigations, you've got to look back to the
Speaker 1: nineteen eighties when a brit named Alec Jefferies, who now
Speaker 1: you may refer to as Professor Sir Alec John Jefferies
Speaker 1: f R S hang okay, good, Professor Sir Alec John Jeffries, FRS. Uh,
Speaker 1: that would be his full title. Now. He hit upon
Speaker 1: the idea of using DNA as a means of genetic fingerprinting,
Speaker 1: and he realized that the unique sequences of DNA could
Speaker 1: serve as a means to link an individual to a
Speaker 1: scene where DNA samples were found. And his process was
Speaker 1: first applied in the court system in nineteen eight five.
Speaker 1: In that case, it was an it was an immigration case.
Speaker 1: It wasn't like a murder or a rape or something
Speaker 1: like that. It was to ascertain if the identity of
Speaker 1: a British boy was actually related to a family who
Speaker 1: had originally immigrated to the United Kingdom from elsewhere. And
Speaker 1: he did. Uh. The first time it was used in
Speaker 1: a criminal case would be nine seven. That was yeah,
Speaker 1: not not long after, and that wasn't a case. Uh.
Speaker 1: The The suspect was named Colin Pitchfork, which is a
Speaker 1: heck of a name. Talking about nominative determinism, Yeah, and
Speaker 1: he was arrested on suspicion of rape and murder, and
Speaker 1: he was the first criminal cut as a result of
Speaker 1: DNA screening. So this was DNA screen that led to
Speaker 1: his capture. He actually confessed to his crimes, so the
Speaker 1: DNA didn't lead to his conviction. He confessed UH and
Speaker 1: he received life in prison as a result. So I
Speaker 1: wanted to talk a little bit before we get into
Speaker 1: some of the pros and cons about what actually happens
Speaker 1: with DNA because you hear like DNA forensics and you're like, well,
Speaker 1: what goes into that? Yeah, this is a great thing
Speaker 1: to contextualize right now because there are a lot of
Speaker 1: fans and tech stuff who have probably seen and scoffed
Speaker 1: at the various entertaining but inaccurate crimes shows c s I,
Speaker 1: CSI being the big one, Like they're there are are
Speaker 1: FRIENDSIC specialists who say that c s I is probably
Speaker 1: one of the most damaging things that have happened to
Speaker 1: their their career path ever because people have unrealistic expectations, specifically,
Speaker 1: juries have unrealistic expectations, which can hurt a trial case
Speaker 1: because juries will often one want DNA UH data when
Speaker 1: it's not even relevant to a case. Like they're like
Speaker 1: it's not necessary for them to make a determination in
Speaker 1: a case, but they want it because it's one of
Speaker 1: those things that people associate with. Oh, d NA gets
Speaker 1: you the the locked in answer was that person there
Speaker 1: were they not there? Um, just run the DNA enhanced
Speaker 1: the photograph. I see what the problem right? Exactly. Yeah,
Speaker 1: let's pull up one of those three dimensional holographic images.
Speaker 1: We're just we're just throw every single science fiction CSI
Speaker 1: trope in there, so early friends. Now, this actually used
Speaker 1: a process called restriction fragment length polymorphism or r f LP,
Speaker 1: and that involves taking a sample of DNA that has
Speaker 1: repeating base pairs, like they can repeat from anywhere between
Speaker 1: one and thirty times. They're called variable number tandem repeats
Speaker 1: or v N t r s. And what they would
Speaker 1: do is they would dissolve this DNA in an enzyme
Speaker 1: to break the strand at specific locations along that the DNA.
Speaker 1: So uh saying like, um, when there are this many repetitions,
Speaker 1: this enzyme is going to break the strand at that point,
Speaker 1: so that way we can measure how long the strand
Speaker 1: DNA is in and out point. Yeah, So imagine that
Speaker 1: you've got like a ribbon, right, And let's say that
Speaker 1: little ribbon is maybe three ft long, and you're going
Speaker 1: to cut out a six inch segment of that ribbon.
Speaker 1: Use this enzyme, and it cuts it at the very
Speaker 1: specific locations along that strand that you want. You do
Speaker 1: the same thing with the material that was left behind
Speaker 1: at the scene. So let's say you've got you've got
Speaker 1: your your DNA sample from your suspect, you've got the
Speaker 1: sample from the scene, and you compare the two and
Speaker 1: you're essentially measuring them against each other, like literally measuring
Speaker 1: the length of them, because it's those repeating pairs that
Speaker 1: determine how long that segment is. So if the two
Speaker 1: are about the same length, or actually they are the
Speaker 1: same length, then you know, or at least you you
Speaker 1: have a good uh inclination to say that this person
Speaker 1: was the one who left behind that DNA. That's not
Speaker 1: really used that frequently anymore, but more frequently now we
Speaker 1: use a method called short tandem repeat analysis, which is
Speaker 1: more reliable, more popular, And in this method, analysts take
Speaker 1: a sample of DNA and they count the repetition of
Speaker 1: those base pairs along certain locations the loci of that sample.
Speaker 1: So for or five base pair repeats, like where you
Speaker 1: get you know, your your those nucleo tied pairings I
Speaker 1: talked about, sometimes those pairings repeat in a sequence, right,
Speaker 1: They look for uh, preferably four or five base pair
Speaker 1: repeat segments. So that way, because it's less likely than
Speaker 1: if you would have two or three in a row. Yeah,
Speaker 1: the more you have in a row, the less likely
Speaker 1: you're going to find that exact same repetition in another
Speaker 1: in an unrelated person's DNA. And these are by the way,
Speaker 1: called tetra nucleotide or penta nucleotide repetitions because of the
Speaker 1: number tetra being four, penta being five. Um. There, those
Speaker 1: are best in order to indicate an accurate match. So
Speaker 1: the FBI, like I said, says, thirteen specific locai to
Speaker 1: find this, you would do this in thirteen different locations
Speaker 1: along the strand of DNA. And if you were to
Speaker 1: find these, uh, these base pair repeats that are identical
Speaker 1: in both and both samples, that's a really good indication
Speaker 1: that they belong to the same person. And this this
Speaker 1: investigation technique, while it is while it's pretty solid and
Speaker 1: there's solid science behind it, it doesn't work in every
Speaker 1: in every case, it's not a silver bullet, and this
Speaker 1: is kind of some dark territory. Yeah yeah. In fact,
Speaker 1: there there are a lot of reasons why, uh, this
Speaker 1: can be this can be problematic. Um. One other thing
Speaker 1: I want to talk about before we get into the challenges,
Speaker 1: specifically things like contamination and chain of possession and this
Speaker 1: chain of custody, thank you, before we get into that,
Speaker 1: is to talk about all right, So you know, I
Speaker 1: gave these these overviews of how they're analyzing the DNA,
Speaker 1: but one of the big issues here is that often
Speaker 1: when you're in the field and you're looking for anything
Speaker 1: that has you know, remnants of DNA on it, you
Speaker 1: may not have a very large sample to work with, Right,
Speaker 1: So you've got a tiny amount of d and a
Speaker 1: how do you make sure you can do the tests
Speaker 1: you need with a tiny little amount? And the answer
Speaker 1: is you duplicate the crap out of it? What how? Yeah? Okay,
Speaker 1: So this is this is gonna get super weird because
Speaker 1: I'm gonna get into molecular biology and chemistry. But starting it,
Speaker 1: I want to Okay. So they use a process called
Speaker 1: polymerase chain reaction or PCR to duplicate a specific region
Speaker 1: of the DNA in a sample. So this process was
Speaker 1: developed in three by Carrie Mullis who actually he won
Speaker 1: a Nobel Prize in chemistry for his work in this field.
Speaker 1: And what they'll do, because they'll take samples of DNA,
Speaker 1: they'll take a string of DNA. So you've got your
Speaker 1: double helix right, and then you heat it to between
Speaker 1: ninety four and ninety six degrees celsius for a few minutes. Yeah,
Speaker 1: so it's almost boiling um for a few minutes. And
Speaker 1: this is to d nature the sample, which means that
Speaker 1: the DNA straightens out, so it's no longer a twisted ladder,
Speaker 1: it's a ladder, and the rungs split apart. So those
Speaker 1: base pairs split and you get two strands, two half
Speaker 1: strands of DNA, all right, So then you end up
Speaker 1: changing the temperature. You lower it to between fifty and
Speaker 1: sixty five degrees celsius for a few minutes. That first
Speaker 1: one only takes a few minutes to so you lower
Speaker 1: it down to fifty to six degrees celsius for a
Speaker 1: few more minutes. That allows the left and right primers.
Speaker 1: These are small sections of DNA that have matching nucleo
Speaker 1: tides to the two separated pieces that you've created. Think
Speaker 1: of them as almost like half zippers. So you've got
Speaker 1: the right and left half of a zipper on either
Speaker 1: like they're they're spreading out there there there's apart from
Speaker 1: one another. You've got a small section that interlocks with
Speaker 1: each side. Because that you've got the the complementary base pairs. Uh,
Speaker 1: those will then connect to those sections. Now that's only
Speaker 1: a tiny little part overall part of the full DNA.
Speaker 1: But um. They then raise the temperature to seventy two
Speaker 1: degrees celsius for a few minutes to allow the tach
Speaker 1: polyme race. Now this is the material that can then
Speaker 1: build and synthesize new DNA to the two separate strands.
Speaker 1: So if you think about it like a video game.
Speaker 1: All right, so you get your little you get your
Speaker 1: little segment that's locked onto the half ladder of DNA,
Speaker 1: the stuff you started off with in the first place.
Speaker 1: At one end of that, imagine that you get a
Speaker 1: little bitty blob, all right, a little big blob just
Speaker 1: builds the corresponding rungs and goes down the line rebuilding
Speaker 1: the DNA. And it doesn't you know, there's one on
Speaker 1: both sides. There's a primer on each half strand of DNA,
Speaker 1: so at the end of this process you end up
Speaker 1: with two strands of d N. A. Okay, we've got
Speaker 1: more to say in this classic episode of tech stuff
Speaker 1: after these quick messages. Now you started with one, but
Speaker 1: because you've used this molecular biology slash chemistry approach, you've
Speaker 1: been able to duplicate it. And then you repeat that process,
Speaker 1: so you do it again. Those two become four, the
Speaker 1: four become a You see how this expands very rapidly.
Speaker 1: You do it over and over, so that way, even
Speaker 1: if you started with a very small sample of DNA,
Speaker 1: by the end you've got plenty to work with, so
Speaker 1: you don't have to worry about you know, we had
Speaker 1: one little drop of sweat at the scene and and
Speaker 1: we blew it on on a test that didn't work out.
Speaker 1: You don't have to worry about that. I'm sorry to
Speaker 1: be like, uh, emotionally or mentally a nine year old here, Jonathan,
Speaker 1: but can we can we make it a booker? I
Speaker 1: just love picture in us as cops or like no,
Speaker 1: no one knows who stole the bus. We have only
Speaker 1: this single the mysterious picker has struck again. Yeah, okay,
Speaker 1: so you're in Yeah, well we weren't talking about urine.
Speaker 1: We were talking about the boogers, all right, you got me.
Speaker 1: But this is but this is a great that that's
Speaker 1: a great explanation of how this occurs. Because given that
Speaker 1: you're essentially destroying the evidence every time that you you
Speaker 1: conduct this kind of this, this kind of investigation, than
Speaker 1: being able to reproduce it is fundamental. Yeah, it's absolutely
Speaker 1: key because again, if you do not have very much
Speaker 1: of that material, then you really have to be careful.
Speaker 1: And there are a lot of things that can complicate this,
Speaker 1: and that's kind of where we were leading to a
Speaker 1: little bit earlier. There are a lot of reasons why
Speaker 1: you cannot just say that DNA forensics is going to
Speaker 1: solve you know, the crimes out there as long as
Speaker 1: someone's left something behind. Because even though it's versatile, even
Speaker 1: though we have this amazing capability, life is weird and
Speaker 1: things can go wrong, and they can go wrong either
Speaker 1: accidentally or on purpose. So one thing that can happen
Speaker 1: is multiple people could be involved in a an incident
Speaker 1: crime of some sort, and so the more people who
Speaker 1: are involved, the harder it is. To be absolutely certain
Speaker 1: that the DNA samples you're working with all linked to
Speaker 1: a specific individual. In fact, there are currently some changes
Speaker 1: in the way DNA can be handled UH in cases
Speaker 1: court cases actually to the point where it's in the
Speaker 1: legal case since UH in Texas and other places as well,
Speaker 1: and so forensics labs are having to put in greater
Speaker 1: restrictions because forensics analysts would go into testify in court
Speaker 1: cases and say, there's a one in a billion chance
Speaker 1: this belonged to someone else. But if you start the
Speaker 1: factor in that there is more than one person's DNA
Speaker 1: found at the scene and the contamination issues that result
Speaker 1: from that, then people would say like, all right, well,
Speaker 1: really it's more like one in a thousand or one
Speaker 1: in a hundred. And then at this point you might say, well,
Speaker 1: the DNA evidence is not strong enough for it to
Speaker 1: be a compelling argument for the guilt or innocence of
Speaker 1: a person, because there's enough like if you're in a
Speaker 1: really dense urban area and you say there's a one
Speaker 1: and a hundred chance that's you know, it's it's hard
Speaker 1: to say that shouldn't introduce reasonable doubt that it doesn't
Speaker 1: meet the burden of reasonable doubts. But and then you
Speaker 1: have to try to chase down all the other possibilities.
Speaker 1: And that's that's if there are multiple people involved. But
Speaker 1: even if there's not multiple people involved, obviously you have
Speaker 1: to be very cognizant of the possibility of contamination. Yeah, okay,
Speaker 1: we we can talk about this a little bit, because
Speaker 1: we this is something that you might not see on
Speaker 1: Hollywood as often as you see it in real life. Yes, exactly, Jonathan.
Speaker 1: So let's say you know the Let's say you're the detective,
Speaker 1: right and Noel is the prosecutor, and I'm the I'm
Speaker 1: the JABRONI at the scene. You was supposed to pick
Speaker 1: up the stuff and bring it, right, Yeah, So you're
Speaker 1: you're your job is to actually go in and collect
Speaker 1: the evidence before anyone else can go through that area, right, Yeah,
Speaker 1: because as soon as you introduce other people, then you've
Speaker 1: introduced other DNA that could be left at the scene.
Speaker 1: But I've been having a I've been having a crazy
Speaker 1: time work lately, and I've been cutting corners a little
Speaker 1: and everybody knows. Nobody said anything yet because it's not
Speaker 1: a big deal yet. But here's what happens. Uh, while
Speaker 1: I'm on while I collect the evidence. Let's see, I
Speaker 1: get blood samples, and I'm on the way back. I
Speaker 1: stop it cook out because my diet is as much
Speaker 1: of a train wreck as my life, and and because
Speaker 1: I'm personable, I shake hands with six people as I'm
Speaker 1: walking back into our holding, right, I don't wash my hands.
Speaker 1: And I also kept the sample for some reason, in
Speaker 1: the bag from cookout. Yeah, that would there there might
Speaker 1: be a chance that that was encountered some form of
Speaker 1: contamination from the scene to the point where you get
Speaker 1: to the lab and then you you run the d NA. Yeah, right, Well,
Speaker 1: clearly the suspect was a roast pig. Right, Yeah, clearly
Speaker 1: suspect was a roast pig. Or even more dangerously, Uh,
Speaker 1: clearly the suspect, Uh, the suspect maybe someone that already
Speaker 1: pings in our database, who just got out of prison
Speaker 1: for grand theft auto and now works out of cookout. Yeah. Yeah,
Speaker 1: that's I mean that that's a you know, it's it
Speaker 1: seems like it's a convoluted example, except for the fact
Speaker 1: that this is the source of stuff that can happen r. Yeah,
Speaker 1: it's not. I would say it's possible, but that one
Speaker 1: is not plausible. No, No, But but the example you
Speaker 1: give does show that there has to be great care
Speaker 1: the the people who come in to collect the evidence
Speaker 1: have to do so before there can be a lot
Speaker 1: of disturbance of the crime scene. Because the more disturbance
Speaker 1: there there is, like I said, the more chances other
Speaker 1: people will leave behind DNA skin cells, or or um
Speaker 1: sweat or blood or whatever it might be. Um might
Speaker 1: be that there were other people who were involved in
Speaker 1: it who have no or you know, people who maybe
Speaker 1: the person who stumbled upon the scene left something behind
Speaker 1: without intending to, like cutting a hand on a on
Speaker 1: a piece of glass or something, letting themselves into see
Speaker 1: what's happened. Yeah, even something as simple as that. So
Speaker 1: there's there's that you have to be aware of contamination there.
Speaker 1: You also have to be aware of contamination through the
Speaker 1: moment you've collected it, all the way through the testing phase.
Speaker 1: So that's where the chain of custody comes in. By
Speaker 1: the way, if you ever see people like putting stuff
Speaker 1: in plastic bags in order to preserve it, that's pretty
Speaker 1: much a fiction because plastic will will contain moisture, right anything,
Speaker 1: Any moisture that's in the bag will stay there and
Speaker 1: moisture can can degrade DNA samples, so usually they're actually
Speaker 1: put in paper, so it's usually a paper envelope or
Speaker 1: a paper bag that's quickly labeled, and then there's this
Speaker 1: chain of custody that must be documented through the entire
Speaker 1: process until it gets to the lab, and then at
Speaker 1: the lab. Even at the lab, they have to be
Speaker 1: very careful with the equipment they're using. They have to
Speaker 1: make certain that it's completely clean and that way you
Speaker 1: don't end up cross contaminating from a previous test into
Speaker 1: your current test. That's happened a couple of times. There
Speaker 1: actually been a couple of cases. Yeah, there was a
Speaker 1: case where, uh, there was a victim of a crime
Speaker 1: and there was another crime that was committed, and the
Speaker 1: initial DNA test results of the crime that was committed
Speaker 1: came back with the victim from the other crime as
Speaker 1: a positive. And they realized that the reason why that
Speaker 1: was happening was that there were two different DNA tests
Speaker 1: that had been performed, and the victim from the first
Speaker 1: one that their DNA had not been completely cleaned out
Speaker 1: of the system before they started doing the next test,
Speaker 1: and so they were getting these false positives, and they
Speaker 1: knew it couldn't have been the victim because the victim
Speaker 1: was the victim was victimized, the victim was not capable
Speaker 1: of committing that crime. Um. So it was already like
Speaker 1: one of those things that proved that there was an
Speaker 1: issue here. And in almost every case, in fact, I'll
Speaker 1: go ahead say the vast majority of cases, this has
Speaker 1: to do with a person either mistakenly or purposefully, not
Speaker 1: following procedure or not making certain that that everything is
Speaker 1: on the up and up. Rather than the process itself
Speaker 1: being a failure, it's it's it's a human error, either
Speaker 1: intentional or otherwise introduced typically um. And so another thing
Speaker 1: that you have to worry about is whether or not
Speaker 1: someone has purposefully introduced DNA. There have been cases where
Speaker 1: in order to try and either uh, to hide one's
Speaker 1: involvement in a crime or to implicate someone else specifically
Speaker 1: in a crime, people have left behind samples of DNA
Speaker 1: in order to throw people, throw investigators off the track.
Speaker 1: Whether again, whether it is to protect yourself, like let's
Speaker 1: say that you committed the crime and you leave behind
Speaker 1: the DNA of you know, your uh, your your hated cousin.
Speaker 1: So that your cousin takes the rapid you don't, or
Speaker 1: you're an investigator and you're like, well, there's this really
Speaker 1: awful guy, and we want to get him for this crime.
Speaker 1: We really like him for this crime, but we don't
Speaker 1: have the direct evidence for him. However, I do have
Speaker 1: this DNA from a separate incident. I can leave this
Speaker 1: behind the crime scene collected, and therefore we can finally
Speaker 1: get the guy. I'm pretty sure he did it anyway,
Speaker 1: you know, solid solid. Yeah. So that's again, this is
Speaker 1: not something that happens all the time. It's not not
Speaker 1: something that's even prevalent, but it's it's one of those
Speaker 1: things that you have to be aware of. That's why
Speaker 1: these things like the chain of custody is so important
Speaker 1: to maintain. I have a question, sure, uh, And I
Speaker 1: don't know if I'm jumping ahead here, no, please ask,
Speaker 1: But I was kind of foreshadowing this while we're asking
Speaker 1: about hair follicles. So the it sounds like the home
Speaker 1: run for UH, for DNA testing would be something, as
Speaker 1: you said, containing living cells, so blood, bodily fluid, stuff
Speaker 1: like that. But if that's a home run, the kind
Speaker 1: of stuff that people are much more likely to leave
Speaker 1: behind would be things like hair follicles or flakes of skin.
Speaker 1: You know, so, what what's the deal with that? How
Speaker 1: how does that work? It's still the same same process
Speaker 1: in the sense that these are things that can leave
Speaker 1: behind traces of DNA, like as long as as long
Speaker 1: as for instance, let's say that you have h you're
Speaker 1: at a murder scene scene and you are you are
Speaker 1: investigating one of the things, You're going to look for
Speaker 1: our traces of any skin under the victim's fingernails, because
Speaker 1: that that's a an indication that the victim fought back
Speaker 1: against his or her murderer and may in fact have
Speaker 1: samples of that skin underneath his or her fingernails. And
Speaker 1: so you can collect that and then do the same
Speaker 1: process I was talking about. You can extract the DNA
Speaker 1: from those cells and then do the same process to
Speaker 1: duplicate that DNA and then run it either against suspects
Speaker 1: DNA or or use a database. We mentioned the databases
Speaker 1: briefly to a little bit about yeah, let's do that,
Speaker 1: because there are a couple of different ones. There there
Speaker 1: are state databases, there's a national database, and then there's
Speaker 1: the FBI's database. Uh So, These are all databases that
Speaker 1: contain the DNA information of various people who have been
Speaker 1: booked for specific types of crimes. It's not every crime.
Speaker 1: Don't worry, the FBI does not have your genetic blueprint
Speaker 1: because one time you purposely parked in a handicap spot.
Speaker 1: Although Jonathan and Nolan I do judge you for that, Yes,
Speaker 1: we think you should definitely never do that. If you don't,
Speaker 1: if you do not have a the handicap label, uh,
Speaker 1: then don't park in that spot. But now these are
Speaker 1: specifically pretty serious crimes where that's really the only way
Speaker 1: that they that that the state or federal government is
Speaker 1: allowed to to collect a DNA sample from you to
Speaker 1: use in this database when they've got a lot of people.
Speaker 1: I've got some statistics here to yeah, please hit me. Okay,
Speaker 1: so let's let's go with the big one, right, Okay,
Speaker 1: The big one here in the States is the National
Speaker 1: DNA Index or in d I S. That's the that's
Speaker 1: the Fed's, that's the FBI. It contains a little under
Speaker 1: twelve million offender profiles, specifically eleven million, eight hundred twenty two,
Speaker 1: nine hundred and twenty seven. It has to a little
Speaker 1: over two million R s D profiles and a little
Speaker 1: over six hundred thousand forensic profiles. That's as of June.
Speaker 1: If you visit the FBI's website, you can learn a
Speaker 1: lot about their biometric analysis, which does also contain print work.
Speaker 1: It's it's sort of a mixtape of all the stuff
Speaker 1: that they could use to investigate. And here's the thing
Speaker 1: you can do if you live in the US and
Speaker 1: you would like to feel a little bit less comfortable
Speaker 1: each day. Okay, it's there's a breakdown by state, so
Speaker 1: you can see how many offender profiles are are located
Speaker 1: in your state. Here in Georgia, in our case, it's
Speaker 1: two hundred nine five thousand, nine hundred and thirty eight.
Speaker 1: Considering the population of Georgia, that is a significant number. Right.
Speaker 1: You can see the forensics profiles, the arrestees. You can
Speaker 1: also see the number of investigations aided in labs participate. Now,
Speaker 1: one of the things I want to point out is
Speaker 1: that this also goes back into the drawbacks or the
Speaker 1: challenges of forensics, is that forensic labs can get really
Speaker 1: backed up with this stuff, Like the backlogs can be
Speaker 1: can be crazy because while I I you know, I
Speaker 1: mentioned that process just for duplicating the DNA. That can
Speaker 1: take a couple of hours to do that process, and
Speaker 1: then of course you've got all the cleaning of the
Speaker 1: material that has to happen in order for you to
Speaker 1: be able to use it again. That's not that doesn't
Speaker 1: even involve the actual analysis of the DNA that tends
Speaker 1: to require a forensic specialist to do this. It's not
Speaker 1: like it's all automated, although there are more and more
Speaker 1: automated systems that help, but generally speaking, it's it's sort
Speaker 1: of an augmented approach where you still have forensic expert
Speaker 1: do the the look you know they're doing. They're looking
Speaker 1: at the DNA to look at those base pairs and
Speaker 1: actually makes certain visually that they are in fact identical.
Speaker 1: So it takes a lot of time. And meanwhile, while
Speaker 1: you're doing all this, more samples are coming in, so
Speaker 1: there's a backlog that starts to build up, and depending
Speaker 1: upon the area and the number of labs that are available,
Speaker 1: it might be a very serious backlog. And there was
Speaker 1: also a pre existing backlog because if we look at
Speaker 1: how recently this occurred and off air we talked about
Speaker 1: this in the course of your research. You send in
Speaker 1: some great stuff about cold cases. Yeah, so there was
Speaker 1: already a built in backlog for this technology, and they're
Speaker 1: already been cases of people who were in jail for years, decades, Yeah,
Speaker 1: who were innocent. Yeah, yeah, where the DNA evidence ended
Speaker 1: up clearing them like it could not possibly have been
Speaker 1: that person. Um. And you know, actually, that's when I
Speaker 1: say that there are some serious restrictions and tax us
Speaker 1: about this multi person DNA approach. It's specifically so that
Speaker 1: there is every attempt to make certain that innocent people
Speaker 1: aren't incarcerated. There is a huge obviously there's a huge
Speaker 1: pressure on law enforcement to to assign guilt and uh
Speaker 1: and bring somebody in for particularly awful crimes. And there's
Speaker 1: an enormous pressure because of course, the community wants to
Speaker 1: feel safe, they want to feel that something is being done.
Speaker 1: That has to be balanced against making sure you get
Speaker 1: the right person. Yeah. Yeah, because we know that we
Speaker 1: live in an age of instant gratification. Yeah, things should
Speaker 1: be right immediately and right the first time and right
Speaker 1: now and right now, yes, the three rights. But unfortunately
Speaker 1: the wheels of justice hows those saying go. Man, they
Speaker 1: grinds low but exceedingly fine. Yes, as opposed to go
Speaker 1: round and round. Yes, the wheels in the bus. I
Speaker 1: was thinking, you know we would be here, terrible lawyers. Yeah,
Speaker 1: we would be Actually, I know I would be. I
Speaker 1: remember participating in a mock trial in school and not
Speaker 1: knowing what the heck I was doing? What was your
Speaker 1: what was your rule? I was defense and it was terrible.
Speaker 1: It was terrible. I did not want to do it.
Speaker 1: I was. I was. I was bullied into it and
Speaker 1: I it was awful. I could see you doing like
Speaker 1: a judge or maybe a bailiff who's over it, like
Speaker 1: sit down. Yeah, no, I was. Uh my my client
Speaker 1: would have gotten the chair. It was terrible for a
Speaker 1: very minor offense too, That's how bad I was. We'll
Speaker 1: wrap up this discussion about DNA forensics after this quick break.
Speaker 1: So I away getting back into DNA forensics. Uh so, yeah,
Speaker 1: you mentioned cold cases. I've got one specific one I'll mention,
Speaker 1: and it's not it's one that has not been um
Speaker 1: seen to completion yet. In other words, there there hasn't
Speaker 1: been a conviction yet in this case, but it does
Speaker 1: show how how far reaching this can go. So in December,
Speaker 1: the body of a young lady named Crystal Lynn bez
Speaker 1: bes Lana, which was found along the Provo River in Utah.
Speaker 1: She was seventeen years old when she was killed, and
Speaker 1: she had been sexually assaulted and murdered, uh perhaps bludgeoned
Speaker 1: to death with rocks. That was what the police believed
Speaker 1: at the time. Now, the original investigator of the crime,
Speaker 1: it was a guy who became the the deputy sheriff,
Speaker 1: I believe, but Todd Bonner decided to continue investigation even
Speaker 1: long after all the leads were drying up, like they
Speaker 1: just could not find any leads, and in a lab
Speaker 1: was able to extract what's called touch DNA. It was
Speaker 1: left behind on a granite rock that the police had
Speaker 1: believed was used in killing this young lady, and the
Speaker 1: lab used a vacuum instrument to pull this touch DNA
Speaker 1: off the granite rock and then put it through this
Speaker 1: analysis process and the results ended up matching DNA from
Speaker 1: a suspect that people were interested in but had no
Speaker 1: direct connection to the crime. The suspect's name was Joseph
Speaker 1: Michael Simpson, and they got the sample DNA from a
Speaker 1: discarded cigarette butt he had tossed us a cigarette but
Speaker 1: the cops scooped it up, they tested the DNA, they
Speaker 1: found a match. They arrested him back in Uh, he
Speaker 1: has a previous conviction for murder. He had actually been
Speaker 1: out on parole for eight months for before Brasilanta, which
Speaker 1: is death. Yeah, so he had been in jail for
Speaker 1: several years but got paroled and then uh, eight months
Speaker 1: later Brisilana, which was dead, and he's been linked to
Speaker 1: this and arrested for the crime. Now that being said,
Speaker 1: the last I checked into this case, you know, that
Speaker 1: was back in the last I checked into this case.
Speaker 1: It's still not it still hasn't been tried. There's been
Speaker 1: request for more evidence on the prosecution side, including uh
Speaker 1: an actual DNA sample from Simpson himself to confirm that
Speaker 1: the findings are in fact accurate, so in other words,
Speaker 1: not just from the cigarette, but but from Simpson in custody.
Speaker 1: And then there's also a request to get a print
Speaker 1: sample because of a partial print that was left behind
Speaker 1: on the victim herself. So, uh, this case is not
Speaker 1: one that's like cut and dry and it's definitive, but
Speaker 1: it does Indica eight that this approach is able to
Speaker 1: start pulling up connections that otherwise would have been unlikely
Speaker 1: or even impossible to make. And this brings us to
Speaker 1: this is just a sidebar, Okay, this brings us to
Speaker 1: a dangerous thing. And you know, of course that I
Speaker 1: who can sometimes be a cartoon of myself and am
Speaker 1: required to mention this. What do you think about the
Speaker 1: idea of blanket DNA sampling? They're taking every citizen. You know,
Speaker 1: some prominent members of the UK legal system have advocated
Speaker 1: this for all British citizens, and Kuwait is doing the
Speaker 1: same thing. Well, let me put it to you this way. Okay.
Speaker 1: There's always the argument that some people will make that
Speaker 1: if you're not doing anything wrong, then what do you
Speaker 1: have to fear? Right, Well, here's what you have to fear,
Speaker 1: I'm gonna tell you. Okay. So there have been at
Speaker 1: least a couple of companies that have shown that through
Speaker 1: a little bit of your DNA, they and do a
Speaker 1: very similar process to duplicating DNA, which means that they
Speaker 1: can synthesize your DNA, which means then that if your
Speaker 1: DNA can be synthesized, it could be created and dropped somewhere.
Speaker 1: And you had never been to that place. Oh wow,
Speaker 1: So you all of a sudden, you get a summons
Speaker 1: for some horrendous crime in uh Iceland or something. You say,
Speaker 1: I've never been Yeah, this is the weirdest thing because
Speaker 1: I've never been there. Like, but this is match to
Speaker 1: your DNA. There's a one and a billion chance that
Speaker 1: someone else did this, um and you you know that's
Speaker 1: that's a thing like, that's we're in a world where
Speaker 1: technologically it is possible to do this. Now, is that
Speaker 1: likely to happen? It's definitely, like and it's in the
Speaker 1: realm of possibility, but not plausibility. However, as long as
Speaker 1: it's possible, then I would argue that it is too
Speaker 1: invasive to demand from your population that everyone submit to
Speaker 1: d n A like submitting a DNA sample and yeah, yeah,
Speaker 1: what about well, let's take a step further. What about
Speaker 1: the idea that there would be what about the idea
Speaker 1: that this stuff, which is you set a blueprint in
Speaker 1: some ways. Also it's it's similar to metadata. Okay, let's
Speaker 1: I can see where you're saying. So the ability then
Speaker 1: to build this enormous sample size let's say the entire
Speaker 1: population of the UK. I think right now they're only
Speaker 1: at maybe five of the population because you have to
Speaker 1: get you know, you have to get pinched. So if
Speaker 1: they had this enormous sample size, then they could start
Speaker 1: comparing and collating and analyzing this stuff on a larger
Speaker 1: scale such that they would be able to possibly again
Speaker 1: possibly not plausibly, uh predict um not epo genetic trends,
Speaker 1: but but predict the likelihood of someone incurring a certain
Speaker 1: disease or something. Well, we're getting into more of a
Speaker 1: genomic sequencing at that point. Yeah, yeah, when you're when
Speaker 1: you're getting into genomic sequencing, it's it's much further, it's
Speaker 1: much it's a much longer process. Because again, this is
Speaker 1: very close to when they call a genetic fingerprinting. It
Speaker 1: makes sense to call it that because you're really just
Speaker 1: looking at the physical resemblance of two strands, right, Like
Speaker 1: like two drawings and there are two drawings of ladders,
Speaker 1: and if the two drawings of ladders are the same,
Speaker 1: then you know you've got a one and a billion
Speaker 1: chance of it not being that person. So that's a
Speaker 1: lot different than going through and identifying things like which
Speaker 1: genes do want I mean, we still don't even know, right,
Speaker 1: So in case you guys are not terribly familiar with
Speaker 1: with genetics. The genes can be pretty complicated things. Think
Speaker 1: about like a giant switchboard. Right, You've got an enormous switchboard,
Speaker 1: and there's like a thousand switches on little metal toggle switches,
Speaker 1: the classic up down toggle switches. Right, unlabeled. That you
Speaker 1: have a bank of lightbulbs in front of you, also unlabeled.
Speaker 1: You flip one switch and one lightbulb comes on. You
Speaker 1: flip a second switch, that lightbulb stays on. Three other
Speaker 1: lightbulbs come on. You turn off the first switch. Only
Speaker 1: one lightbulb goes off, and you start thinking, Okay, wait,
Speaker 1: what how is this? Well, that's the thing about genes
Speaker 1: is that they it's not so simple as to say
Speaker 1: that this one gene is in charge of this one trait.
Speaker 1: It's it can be much more complicated, where it's a
Speaker 1: a selection of genes that some are active, some are
Speaker 1: not active. Um So, because of that, even if you've
Speaker 1: got all the DNA from an entire population, you might
Speaker 1: be able to say, well, this one person suffered from
Speaker 1: a particular inherited disease. Let's examine the DNA and then
Speaker 1: compare it to other people who have suffered from that
Speaker 1: same disease and see where the points of comparison are.
Speaker 1: But that is I mean, it's a monu mental task
Speaker 1: because you just it's beyond taking points along a strand
Speaker 1: and comparing the them against a second sample. Right, it's
Speaker 1: it's a it's another it's almost like a an order
Speaker 1: of magnitude greater in the amount of effort that you
Speaker 1: have to take. Yeah, that's a really good way to
Speaker 1: put it. And that that a squatches some of my
Speaker 1: apien predictions. I do have one other question, all right,
Speaker 1: So we talked about in identical twins, right there, there
Speaker 1: is another, Um, there's another possibility where a person could
Speaker 1: get pinched with the wrong DNA. Are you going with
Speaker 1: a clone? What's your Well, there's a there's another possibility. Wait,
Speaker 1: maybe not. It's not the same as identical twins, but
Speaker 1: it throws another monkey wrench into this. Uh uh chimeras.
Speaker 1: Oh interesting, Yeah, okay, uh, all right, Well I want
Speaker 1: to hear your thought process on this, because this is
Speaker 1: not something I specifically looked into, because chimerism is not
Speaker 1: that it's super rare. Yeah, it's not that it's like
Speaker 1: an episode of SPU for that time. Um, And so yeah,
Speaker 1: it's true though it sounds crazy. And you guys talked
Speaker 1: about this on one of your other shows, right yeah,
Speaker 1: and Forward Thinking, we talked about cameras and yeah. It
Speaker 1: was one of those things where where the more you
Speaker 1: talked about it, the more the more like unsure I
Speaker 1: was that I was reflecting reality because it seems so weird.
Speaker 1: It seems very very strange. So it's a person composed
Speaker 1: of two genetically distinct types of cells. So you might have, um,
Speaker 1: I think the first time I was discovered it was
Speaker 1: related to blood type, right, yeah, I believe, So I
Speaker 1: believe you're correct. So somebody had more than one blood type,
Speaker 1: which is already so trippy to me. I just felt
Speaker 1: like to do the to do just to this topic,
Speaker 1: we would have to mention that that is one of
Speaker 1: those very very exceedingly rare cases where DNA testing is
Speaker 1: not again a silver bullet. Yeah, so you could in
Speaker 1: a bizarre like this is almost like a science fiction novel. Yeah,
Speaker 1: Like to the point where you're like, for this to work,
Speaker 1: so many things would have to fall in line perfectly
Speaker 1: that you might as well say it's impossible. But imagine
Speaker 1: that you have a scenario in which you have a
Speaker 1: chimera and DNA is left behind at the scene, but
Speaker 1: it's only one type of DNA somehow, and then the
Speaker 1: sample they get is somehow just the other type of DNA,
Speaker 1: thus exonerating your your perpetrator um practically. Yeah, there's no,
Speaker 1: it's impossible. The only way that that could really affect
Speaker 1: it is if there were somehow a chimera on the
Speaker 1: involved in this scene and it became a contaminating factors,
Speaker 1: then they would say, well, aside from the victim, it
Speaker 1: seems it appears that there were three people here. Yes,
Speaker 1: that that would certainly, that would certainly cause problems, right,
Speaker 1: that would certainly cause confusion in the whole process. But
Speaker 1: it's also so rare for someone to be a criminal.
Speaker 1: I think it's already yeah, begging beggaring belief right right,
Speaker 1: like like like you you already have. Like if you
Speaker 1: think of the population of people who have some form
Speaker 1: of of that, you know, the chimera DNA thing going on,
Speaker 1: and then within that population, what percentage of those people
Speaker 1: are our master yeah, are are committing these sort of crimes.
Speaker 1: It's got to be pretty pretty small number. Sorry, man,
Speaker 1: I'm sorry, I just had to bring it up. No, No,
Speaker 1: it's fine, like you know, it's it's you know, but
Speaker 1: what if so one other thing I wanted to talk about.
Speaker 1: I almost forgot about this. So did you read up
Speaker 1: about the um the technology of reconstructing a person's face
Speaker 1: using just DNA material, and you, like you you had
Speaker 1: sent that to me off there, And I was initially
Speaker 1: skeptical when I was looking at it, but I'm out.
Speaker 1: It's it's called Snapshot, and it's from a company called
Speaker 1: Parabond and Snapshot what it's what it attempts to do
Speaker 1: is take the information from a DNA sample and create
Speaker 1: a essentially a police sketch of a person, a three
Speaker 1: dimensional uh representation of what a person might look like. Now,
Speaker 1: when I say might look like, you've got to be
Speaker 1: super generous with this because if all you have is
Speaker 1: the DNA, if that's all you have, like you don't
Speaker 1: have any any knowledge of what the person's face looks like,
Speaker 1: otherwise how old they are, they're height, or anything. What
Speaker 1: you'll be able to do is probably approximate their skin tone,
Speaker 1: their ethnicity, their gender, at least their biological gender there,
Speaker 1: they're hair color, their eye color, that kind of stuff,
Speaker 1: whether or not they have freckles, that kind of thing.
Speaker 1: But beyond that, you're not gonna be able to tell
Speaker 1: their age. You're not gonna tell their higher weight, So
Speaker 1: you can't you can't tell how heavy said or thin
Speaker 1: they may be. How you don't know how much how
Speaker 1: much like what sort of wrinkles would you need to
Speaker 1: add in if they're you know, if they're older. Yeah,
Speaker 1: you wouldn't know any of that. Uh, And you wouldn't
Speaker 1: know their skull shape, Like you wouldn't know their face shape, right,
Speaker 1: like the DNA wouldn't. So, so what you can do
Speaker 1: is create like a very generic looking person but with
Speaker 1: those traits. So it may not be so useful in
Speaker 1: the sense of using this as a means of trying
Speaker 1: to track down the suspect there may not come in handy.
Speaker 1: Where it might help is if you have unidentified remains.
Speaker 1: So let's say you've found the remains of a person
Speaker 1: and you're able to extract some DNA information, but you're
Speaker 1: not able to ascertain the identity of this this person. Uh.
Speaker 1: This would allow you once if you have the person's
Speaker 1: like skull, like if if that's part of the remains
Speaker 1: that are left behind, you then know at least the
Speaker 1: dimensions of the skull. And there are also other technologies
Speaker 1: that allow people to approximate lot of person's face looks
Speaker 1: like based upon their skull shape. So combining those two
Speaker 1: where you you say, all right, this is what they're
Speaker 1: they probably look like based upon the the shape of
Speaker 1: their skull. Plus here are their characteristics that they had
Speaker 1: according to their d n A, then you might be
Speaker 1: able to create a few different looks for that particular
Speaker 1: individual that might help in identifying who that person was. Yeah,
Speaker 1: and that that I think is the most tremendous possibility
Speaker 1: of this technology, absolutely right, because we're seeing already that
Speaker 1: the study of d n A and and the application
Speaker 1: of this sort of science has fundamentally changed the nature
Speaker 1: of crime and investor negation. Yeah, to the point where
Speaker 1: again it can affect juries, uh and there and their
Speaker 1: perception of a case to the So so it can
Speaker 1: be a frustration, right, like if you have if you
Speaker 1: have other lines of evidence that clearly indicate that the
Speaker 1: person accused of the crime has committed it, but because
Speaker 1: there was there was no DNA evidence, or maybe there
Speaker 1: was some problem with the chain of custody, that can
Speaker 1: create enough doubt in a jury's mind, a jury that's
Speaker 1: been conditioned to believe the DNA evidence is the end
Speaker 1: all be all that it can it can cause problems
Speaker 1: in that case. This is this is the thing, is
Speaker 1: that human beings were messy, right, Like we're not just
Speaker 1: messy and that we leave DNA behind. We're messy in
Speaker 1: the way we try to process information. And so sometimes
Speaker 1: you know, when you go through an entire process of
Speaker 1: when a crime is committed, to figuring out who potentially
Speaker 1: did it, to apprehend that person, to then trying that
Speaker 1: person for the crime, to then deciding whether or not
Speaker 1: they're guilty. I mean, there's so much stuff going on
Speaker 1: through that whole process. I hope you enjoyed that classic
Speaker 1: episode with Ben Bolan guest hosting. Was a lot of fun.
Speaker 1: Having him on always is fun. Occasionally you might hear
Speaker 1: me pop on his show Ridiculous History as a character
Speaker 1: called the Quister, where I am even more obnoxious than
Speaker 1: I am on this show. And I know that's hard
Speaker 1: to believe, but it is true. If you would like
Speaker 1: to reach out with suggestions for topics I should cover
Speaker 1: on future episodes of Tech Stuff, there are a couple
Speaker 1: of different ways of doing that one is to download
Speaker 1: the I heart Radio app, navigate over to the text
Speaker 1: Stuff page, use little microphone icon, record a message up
Speaker 1: to thirty seconds in length letting me know what you
Speaker 1: would like me to cover, or you can reach out
Speaker 1: on Twitter. The handle for the show is text Stuff
Speaker 1: H s W and I'll talk to you again really soon.
Speaker 1: Text Stuff is an I heart Radio production. For more
Speaker 1: podcasts from I heart Radio, visit the i heart Radio app,
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.