S1: A listener production.
S2: Welcome to Crime Insider's forensics. For those joining us for
S2: the first time. My name's Catherine Fox. I'm a former GP,
S2: crime author and screenwriter. I'm enthralled by forensics and have
S2: spent thousands of hours researching for books and screenplays. So
S2: I thought, why not turn my research into a podcast?
S2: Every week you'll be joining me in discovering how forensic
S2: science is helping solve high profile crimes in Australia and
S2: around the world. This week, the fingerprint science behind one
S2: of the world's most contentious homicide investigations.
S3: It was just that one fingerprint and how it was
S3: used in this particular case that created enough doubt in
S3: the jury's mind that the only outcome that they could
S3: proceed with was an acquittal.
S2: Doctor Scott Chadwick is an expert in finger mark detection
S2: at the UTS centre for Forensic Science. His research focuses
S2: on pushing the boundaries of fingerprint analysis, from improving conventional
S2: fingerprint detection methods to producing prints on challenging surfaces.
S3: We're actually able to recover fingerprints from documents for up
S3: to 70 years.
S2: Our conversation begins with the officially closed but unsolved Engelbart's
S2: murder investigation. It's a story where a single fingerprint affected
S2: the outcome and determined whether the suspected killer was acquitted
S2: or convicted. Ingle Lotz was a 22 year old master's student.
S2: She was studying mathematics in University town of Stellenbosch in
S2: South Africa. She was found in her very secure apartment block,
S2: sitting on her lounge cross-legged with a magazine in front
S2: of her in a very relaxed position. But the tragedy
S2: of this is that she was bludgeoned and stabbed multiple
S2: times in what seems like a very violent, very targeted attack.
S2: And police automatically looked, as they usually do, to the
S2: people who were closest to her. And as it transpires,
S2: her boyfriend, Fred VanDerveer, had a fight with her that morning.
S2: She'd written a note to him and told someone she'd
S2: met at lunch that their relationship was over, so police
S2: automatically targeted him as the most likely suspect. But can
S2: you please talk about why that was not the wisest
S2: move for the police to make at the time?
S3: Yeah. So a key part of this particular case was
S3: that they recovered a fingerprint on a DVD case. So
S3: the events leading up to her murder in the morning,
S3: she went to university. And as you said, she had
S3: her lunch with a friend. And then on her way home,
S3: she went to a video store and picked up a
S3: DVD to watch that evening. And when she came home
S3: where she was living, it was a secure compound. There
S3: wasn't any signs of forced entry. You needed a.
S2: Remote control to enter and exit the compound. Yes.
S3: It wasn't CCTV cameras at that particular time. It was
S3: in the early 2000. But whoever committed the crime, it's
S3: believed that Inga knew that person.
S2: So they had access to this community?
S3: Yes. Or Inga recognized that person and then let them
S3: into her house.
S2: We should probably say, too, that she was wearing pajamas,
S2: and she was apparently a devoted Christian and very modest,
S2: and her boyfriend was even more conservative and didn't approve
S2: of her wearing, um, thin straps. And unless he was
S2: with her. So to be in a position where she
S2: was wearing very casual pajamas. Given the context that she
S2: and her partner also allegedly had no physical contact because
S2: he believed that any physical contact could lead to sexual
S2: activity in a relationship, she therefore, in that context, it
S2: wasn't just like anybody sitting there in their pajamas. For her,
S2: this was an intimate situation. So I think that's easier
S2: to assume that someone who was in her apartment was
S2: let in. And to be in that casual position, sitting,
S2: reading a magazine. She obviously didn't suspect anything.
S3: Yeah, absolutely. She was obviously very comfortable in the person
S3: that she invited in. If you're in your pajamas, you're
S3: in a state of relative undress, but you would be
S3: comfortable with the person. Otherwise you put a jacket on
S3: or you'd want to cover yourself and the other side
S3: to interpret it is that perhaps she wasn't expecting a
S3: visitor that evening, in that she was in her pajamas
S3: to watch a movie at home and then go to
S3: bed and not expecting someone to come over.
S2: From what I've read at the scene, there were seven
S2: police plodding through the crime scene, and they weren't necessarily experienced,
S2: but obviously they had to try and find evidence, and
S2: fingerprints were one of the first things they started with.
S2: So can you talk about the fingerprints that were taken,
S2: how they were identified and where they were taken from?
S3: The fingerprints that were taken, or a key fingerprint that
S3: was recovered from the crime scene, according to police, was
S3: that there was a fingerprint that was linked to Fred,
S3: her then boyfriend found on the DVD case. So it's
S3: important when we think about this type of evidence, is
S3: that we can't specifically date when a fingerprint is deposited.
S3: We don't have that technology to be able to do that.
S3: So sometimes we need to use additional information around the
S3: context of the case to help us recreate events or
S3: understand what happened during the events of a crime. And so,
S3: because he had been there earlier that day, recovering a
S3: fingerprint at the house could be explained away, is that
S3: it was deposited before the crime. Uh, it was just
S3: their usual, you know, activities that they were doing together.
S2: You expect to find them on the bathroom door or
S2: a sink, maybe?
S3: Yeah. Just. I mean, we touch a whole bunch of
S3: things when we enter rooms. If we see that tables,
S3: we do it completely unconsciously. So the key part here
S3: was that because she had gone to the video store
S3: that afternoon and rented that specific DVD, recovering a fingerprint
S3: that matched Fred on the DVD case, put him in
S3: that apartment in that afternoon, and it was indicating that
S3: he was there after the initial fight and disagreement in
S3: the morning, and then also her day at university at lunchtime.
S2: And he'd been denying being in the house since then.
S3: Yes, absolutely. So it was, uh, was putting him in
S3: her apartment that afternoon and it went against what his
S3: story was.
S2: So when the fingerprint is go in, what is their
S2: process to take fingerprints and what do they target.
S3: With any sort of examination? The first thing that we
S3: would always do is do an optical examination. So we
S3: will do a light search. So using very basic colored torches,
S3: the crime scene investigators will do a search. Now the
S3: areas that they're going to focus on usually are around
S3: points of entry or places where it's likely that there's
S3: been contact with someone's hand. So door frames not so
S3: much door handles just because they tend to be curved
S3: and really tightly curved surfaces are hard for us to
S3: image and.
S2: Recover even though they're metal.
S3: Yeah, even though they're metal. Whereas if you open a door,
S3: you'll often push the handle down and then use your
S3: other hand to to push the door open. So usually
S3: around shoulder height is where they'll they'll focus specifically around
S3: window frames, particularly at the base of the frame. If
S3: somebody is climbing through a window, they'll put their hands
S3: on the frame and then lift themselves up to get
S3: inside or to exit. And it's usually just those places
S3: where it's suspected of high touch. But then where the
S3: likelihood of recovering a usable fingerprint is going to be high. And.
S3: Focusing also on items of interest when they do their
S3: initial examination. There is if we go and try to
S3: develop everything, we're going to create a big mess, but
S3: we're also going to create, if there are fingerprints that
S3: we recover, is it going to be useful? So there
S3: is a bit of hypothesis formation that the crime scene
S3: examiners will do, and asking questions of where looking at
S3: the scene, looking at the the type of crime that occurred,
S3: where is the most likely place to recover a usable fingerprint.
S2: So what are you actually using to recover the fingerprints?
S3: So at a crime scene, the most common development method
S3: that we will use is powdering. And powdering is where
S3: we would use a very fine powder. In a lot
S3: of cases we have black fingerprint powder, which is a
S3: form of activated charcoal which is really useful for surfaces
S3: like metal, like glass, anything that's light in color.
S2: Because you get a contrast.
S3: Yeah, you can image it. You have your your white
S3: light and you can image it with your digital cameras very,
S3: very easily. If the surface is dark or it's reflective,
S3: if it's got background, we might use other more specialized powders. Um,
S3: they might just be a white powder. So one we
S3: use is titanium dioxide. Or we will use what we
S3: call fluorescent or luminescent powders. And this is where using
S3: the colored lights and special filters on the camera, we'll
S3: be able to remove any interference from the surface to
S3: enhance the contrast.
S2: So you remove reflection and other confounding variables.
S3: Yeah. So if something is very highly patterned or textured,
S3: if you have a regular black or white powder, the
S3: background that that finger mark was deposited on can sometimes interfere.
S3: And the goal here is to try and get the
S3: highest quality finger mark so that we have the best
S3: chances of making an identification. And so by using fluorescent
S3: or luminescent powders, we can reduce the interference from the
S3: background and then produce a mark of hopefully identifiable quality.
S2: Do any of those techniques ruin the items?
S3: The ones that we use at the crime scene can
S3: be cleaned very easily. There are usually just wiped down
S3: with some disinfectant and spray and wipe. But if we're
S3: collecting samples to then analyze at the laboratory. So certain
S3: types of evidence we can't develop with powders. So we
S3: would have to collect it and take it to the laboratory.
S3: And in a lot of the cases for the laboratory
S3: development methods, they're damaged beyond repair or they're exposed to
S3: chemicals which are hazardous, that we wouldn't feel comfortable returning
S3: back to individuals because it may not be safe for
S3: them to to use them.
S2: So in this scene, I mean, the first thought I
S2: had for a DVD case is they're generally generic. This
S2: was a generic DVD case, so the person at the
S2: store just grabs the next one that's empty. So it's
S2: not specific. So you can't then go back. Who who
S2: borrowed that DVD before you, and how many fingerprints on
S2: earth would be on a DVD case that had been
S2: hired out repeatedly, and chances are not wiped down very frequently?
S2: I just thought it was interesting that they targeted a
S2: DVD case, and they may not have known necessarily when
S2: that was rented.
S3: Yeah, it definitely raised some questions, but it helped the
S3: story that the police were wanting to.
S2: Fit it.
S3: Exactly because it put Fred in that location in that
S3: afternoon where he didn't have an alibi or his story
S3: didn't match up. So it was very much a gotcha
S3: type piece. It was what they would call a smoking gun,
S3: I guess, because it it put him in that apartment
S3: that afternoon and it could not be explained. He'd already
S3: given his story and said he wasn't there, but this
S3: was seen as well. According to the evidence that we've recovered,
S3: you were there. You're lying. That implies some level of guilt.
S2: So you'd like DNA. People assume that that's, um, incontrovertible
S2: that that that is the absolute gotcha moment. So why
S2: was that challenged in this case?
S3: Yeah. So there was a few interesting things with this
S3: particular fingerprint. So the first one was that the evidence
S3: that the police submitted, there was no recorded image of
S3: the fingerprint on the DVD case. So when we would
S3: go to a crime scene, if we develop a fingerprint
S3: at the crime scene, we will always take an image
S3: of that fingerprint, because that is a direct indication that
S3: we have recovered and developed that fingerprint on that particular surface.
S2: It's shareable, it's reproducible.
S3: It's it's trackable. It's it's will have an individual number.
S3: And we can then add that into any sort of
S3: crime scene reconstructions that we do. It helps us understand
S3: what happened.
S2: And you have a fixed chain of evidence.
S3: Exactly. We have a chain of custody and the image
S3: is recorded. It's linked to that particular evidence item. Timed times. Yep.
S3: Time stamped everything. So it's trackable. Essentially, once we image
S3: that fingerprint at the scene, what would happen is in
S3: some cases they might take a lift. So using either
S3: a gelatin lift or a special type of of tape adhesive, they.
S3: It will take that powdered finger mark or fingerprint and
S3: lift it off the surface to then take back to
S3: the laboratory if they wanted to do any further imaging
S3: or analysis in case there was, you know, an issue
S3: at the crime scene with the photography. So in this
S3: particular case, there was no recorded image of the developed
S3: fingerprint at the crime scene. There was only an image
S3: of the tape lift. And that in itself introduced some
S3: doubt into that piece of evidence.
S2: Questioning from what? Was that actual fingerprint lifted? Yeah.
S3: So the police were reporting that it was recovered from
S3: the DVD case, but without an actual image of that
S3: develop marked on the DVD case, it could have come
S3: from anywhere.
S2: Is there a way of differentiating whether this was taken
S2: from a DVD case versus another item in the apartment?
S3: Yeah. So in this particular case, because of that initial doubt,
S3: Fred's defense team reached out to a range of international
S3: fingerprint experts because there were some interesting artifacts that couldn't
S3: be clearly explained by police on the on the lift.
S3: In those particular cases, the lifted print had a thin
S3: white line at the top and a smudging that occurred
S3: on that same line. The other point that was curious,
S3: but could potentially be explained, was the fingerprint orientation was
S3: slightly curved, and there were just some questions about how
S3: this could have happened or how this could have been
S3: recovered from a DVD case. So the fingerprint experts went
S3: about and conducted a series of experiments using a range
S3: of DVD cases, different types of plastics, different types of shapes.
S2: Which are flat DVD cases.
S3: Which which are flat, and then try different orientations of
S3: how they held the DVD case, the positions that they
S3: held it in.
S4: Yeah.
S3: And did an experiment and did a scientific experiment to
S3: try and reproduce those three factors. The thin white line,
S3: the smudge that occurred on the white line and the
S3: curvature of the finger. And throughout all of their experiments,
S3: they were not able to reproduce those three artifacts in
S3: a repeatable and consistent manner in any of the circumstances
S3: that they conducted the experiment. And it wasn't until they
S3: trialed other types of surfaces that they were able to
S3: reproduce some of those characteristics, and the one where they
S3: were able to successfully reproduce those characteristics was by lifting
S3: a fingerprint off a glass.
S2: A rounded glass, a.
S3: Drinking glass, yes.
S2: So why is a fingerprint on a rounded glass so
S2: very different?
S3: Well, it's to do with the characteristics of the surface
S3: that we deposit the fingerprint on. So as you mentioned earlier,
S3: a DVD case is a very flat and smooth surface.
S3: There is the, the edges of the of the case,
S3: but then the edges are also quite rounded and they're
S3: not a thin sort of edge. It's more yeah, just
S3: a bit more of a curved edge. Whereas the drinking
S3: glasses that we have, well, they're quite curved in their nature.
S3: And the lip of the glass is also quite thin.
S3: So the structure of these items are very, very different.
S3: And how we handle them, how we use them will
S3: leave different types of impressions when we touch them.
S2: And from different parts of the fingers as well.
S3: Yeah, if we think about how we hold certain items.
S3: So if we're holding a DVD case, we might put
S3: our thumb on the front and have our four fingers
S3: at the back and our fingers will be quite straight
S3: along the straight edge. Whereas if we think about how
S3: we hold a glass again, we might have that same
S3: position where our thumb is at the front, but the
S3: curvature of our fingers as it wraps around the glass
S3: is going to be different. The parts of our finger
S3: that are in contact with the glass will also be
S3: slightly different. Our fingers tend to curve slightly upwards when
S3: we have curved surfaces, particularly the the index finger compared
S3: to the other fingers that we have and. If we
S3: take it off, we'll see more of the towards the palm.
S2: Because that's what we we don't normally trust for the
S2: drinking vessel. If it's glass. We normally take the weight
S2: in our palm. Yeah. Rather than rely on a couple
S2: of fingers to hold it.
S3: Yeah, exactly. So when they did this experiment, they lift,
S3: they powdered the fingerprint off the glass. Uh, they then
S3: lifted it. And what they found was the thin white
S3: line at the top was actually the lip of the glass,
S3: because there would be some powder developing, just sort of
S3: sticking to the edge. Usually when we drink, there's some
S3: moisture there. And powder fingerprint powders are adhering to moisture.
S3: It's not a chemical reaction that's occurring specifically with the fingerprint.
S3: It's just sticking to the sweat and oils or just
S3: any moisture that it can get into contact with. So
S3: there was some thin powder being developed on the lip
S3: of the glass. And then that that smudge that was
S3: occurring across the thin white line was actually a lip
S3: print that had been developed because as you drink a glass,
S3: you take your lip to the edge and you're leaving behind,
S3: not as identifiable as a fingerprint, but still able to
S3: be developed with with powder.
S2: So if that was found in the apartment and the
S2: police allegedly took it from a glass, not from the
S2: DVD case, then that blows a massive hole in their
S2: prosecutors and story. In terms of glasses in houses, does
S2: a dishwasher remove every fingerprint? Does rinsing remove fingerprints? What
S2: is likely to be still there after things have been washed.
S3: In fingerprint science? There's there's two sort of divisions. There's
S3: what we call non-porous surfaces. So these are things like metal, glass, uh,
S3: ceramic tiles where when we touch that surface, the sweats
S3: and oils from our fingerprints will just sit on the
S3: surface and it won't seep into that surface, so they're
S3: not well protected. So if we wash that glass or
S3: that item, we would not be able to recover a
S3: fingerprint afterwards because the sweats and oils have been washed
S3: away completely.
S2: Unless that person puts it in the draining tray or
S2: puts it in the cupboard again. So then you've got
S2: contact again.
S3: Yeah, since the last contact. And then the other area
S3: of fingerprints is looking at the other area of surfaces
S3: is the porous. And this is things like paper and cardboard.
S3: Now in these particular surfaces the sweats and oils will
S3: seep into the surface and get trapped in the paper
S3: or cardboard fibers. And in those instances they're protected. So
S3: we're actually able to recover fingerprints from documents for up
S3: to 70 years using specialized chemical detection techniques. So in
S3: those instances, if you wash it in water, if you
S3: throw it in a sink and try and wash it
S3: up and then dry it later, some of the components
S3: of the fingerprint will be washed away, but some components
S3: will still remain, and we can choose different development techniques
S3: to target specific components.
S2: This was a big, big trial with lots of international
S2: experts involved, which is unusual.
S3: Absolutely.
S2: So what happened when these international experts reproduced and challenged
S2: whether or not that fingerprint was on the DVD?
S3: Yeah. So it created enough doubt in the case for
S3: a mistrial to proceed because. The police were not able
S3: to produce that image of the fingerprint being recovered or
S3: the fingerprint being developed on the DVD case. And so
S3: when the police were asked to provide this piece of
S3: evidence and they were not able to that particular evidence,
S3: the fingerprints was stricken from the the proceedings and could
S3: not be considered in the judgment. And without that timing
S3: of the fingerprint being on the DVD case in that
S3: particular afternoon, other elements became a little bit more circumstantial.
S3: It could be explained away. And so it created enough
S3: doubt in the minds of the judge and the jury
S3: that it was not able to move to a conviction.
S2: We should probably mention what happened to the DVD case.
S2: Why was that not held in evidence?
S3: So there's two minds here in that the DVD case
S3: in question either wasn't initially powdered and there wasn't any
S3: finger mark recovered on there, or it was powdered and
S3: followed the particular proceedings, but there was no usable or
S3: identifiable fingerprints developed. And that couldn't specifically link to Fred because,
S3: as you've mentioned, if you pick up a DVD from
S3: a video store, it's very unlikely to have been cleaned earlier.
S3: So there may be a lot of background fingerprints on there.
S3: So there may have been evidence that he touched it,
S3: but it wasn't enough. There wasn't enough identifiable information to
S3: confirm that it was Fred's. So this was seen as
S3: a way to assure an outcome by having an identifiable
S3: fingerprint that they said came from the DVD case, which
S3: would then corroborate the story that the prosecution were wanting
S3: to put forward.
S2: One of the things that I found incomprehensible in this
S2: case was that apparently the police handed back the DVD
S2: case to the DVD shop.
S3: Yeah. We talked earlier about evidence integrity and chain of custody. Yes.
S3: And that's obviously an example of what not to do.
S3: And in particular, it's probably because just to speculate that
S3: they didn't think it was important or it didn't have
S3: value at that particular point in time.
S2: Presumably if they had dusted it, they would have had
S2: to have cleaned it before returning it to the DVD store. Yeah.
S2: So the whole story really does fall apart, doesn't it?
S2: In terms of credibility and plausibility on the part of
S2: the police's behaviour?
S3: Yeah, absolutely. It really put a spotlight on the police
S3: conducting that investigation and for good reason, because fingerprints are
S3: an important piece of evidence in a lot of criminal investigations,
S3: and they carry a significant amount of weight because they
S3: can be used to identify an individual when we use
S3: it appropriately and for the purposes that they are intended.
S3: They are an incredible, useful tool. But they can be
S3: manipulated or used inappropriately to achieve a particular outcome that
S3: benefits a party. And when we use science in that way,
S3: or use evidence like fingerprints or DNA, it's where we
S3: get cases like this and it brings the entire forensic
S3: discipline into disrepute and dis, you know, disregard. So it
S3: just really highlights the value that forensic science is an
S3: important tool in criminal investigation, but it always comes down
S3: to who wields it and what their intentions are. And
S3: as a forensic scientist, you need to be unbiased in
S3: what you do. And while in some cases you assist
S3: police in investigations, you're not there to achieve a particular
S3: outcome or get a specific conviction. That's not not our role.
S2: It seems to me it's a lot in some way.
S2: There are parallels with the OJ Simpson case in that
S2: part of the evidence found, as I understand it in
S2: OJ's trial, was that someone had deposited a bit of blood,
S2: but it actually had the preservative from a blood tube taken,
S2: and to have done that is beyond my comprehension. But
S2: it then absolutely tainted all of the evidence, because if
S2: one bit of evidence was fraudulently placed, what else was
S2: rigged and and incorrect and inaccurate and what else was
S2: a fed up? So you can see why a jury
S2: would suddenly doubt the science.
S3: Yeah, absolutely. And I think the parallel to the OJ
S3: Simpson case is is accurate. It's important. And it raises
S3: another point in that the crime scene is an important
S3: part of the investigations that we do. And. It's not
S3: something that we can go back to and retrial or
S3: re if we make a mistake at the crime scene,
S3: that mistake carries all the way through the investigation, and
S3: we will only get one shot to do things appropriately.
S3: And by, uh, you know, by the standards that we
S3: have and in the OJ Simpson case as well, there
S3: was quite a lot of issues around the crime scene
S3: investigation and how that was investigated. And once you make
S3: those mistakes, the genie's out of the bottle. You can't
S3: put it back in. And it's the same in the
S3: Engelhardt case where. That initial crime scene was questionable in
S3: that investigation. And while it may be that Fred was
S3: guilty of that particular crime because they didn't follow the
S3: right procedures, didn't do as they should have, they wanted
S3: a particular outcome or a focused decision. They've messed up
S3: their chance to now go back and give justice.
S2: He was acquitted. So he can never be tried again.
S3: Yes, absolutely. And to this day, it's still it's an
S3: unsolved case. And there's no.
S2: But it's closed. Yeah, it's a closed case, but it's unsolved.
S2: I find that really sad for the family. And apparently
S2: the family did try to sue Fred VanDerveer in civil court,
S2: but it just became too traumatic for the parents.
S3: Yeah, it's absolutely heartbreaking that all of the other evidence
S3: that you've mentioned indicate that it was Fred. There's no
S3: other suspects in this particular case, but it was just
S3: that one fingerprint and how it was used in this
S3: particular case that created enough doubt in the judge and
S3: jury's mind that the only outcome that they could proceed
S3: with through the legal system was an acquittal, because of
S3: the misuse of that particular piece of evidence.
S2: And the defense's job is really to just raise reasonable doubt,
S2: but the prosecutor has to prove beyond reasonable doubt. So
S2: if you muck up any of the forensic science, you've
S2: left this gaping hole in the entire case, and intelligent
S2: defense and objective scientists hopefully will be able to raise
S2: those questions that should have been asked initially.
S3: Yeah, absolutely. And I think that's the importance of science
S3: in in the courtroom and being objective, because if we
S3: flip it in an instance where an individual may have
S3: been innocent and that particular item is misused and we
S3: don't cast a reasonable doubt, that item remains, then we
S3: have instances where people are imprisoned unjustly. Exactly.
S2: In terms of other ways of getting fingerprints in a
S2: crime scene like that. Having lots. Could there have been
S2: any fingerprints on her? On her body, on her throat.
S2: Neck where she was assaulted?
S3: Um, so it is possible the challenge for us, from
S3: a forensic science perspective, is there is no reliable method
S3: for us to recover fingerprints on the surface of other
S3: people's skin. And the reason is, is that the components
S3: that we target, whether it's just general moisture with powdering
S3: or whether it's the sweats and oils from our skin,
S3: where they're going to be present on other people's skin
S3: as well. And so when we try to use those
S3: same methods and techniques, we we are going to be
S3: more developing that individual's sweats and oils as opposed to
S3: the person who might have touched them that have had
S3: done it. So that's always a challenge for us. And
S3: that recovering fingerprints from the surface of someone's skin is
S3: something that we're just not able to do at this
S3: point in time, reliably.
S2: Yeah, exactly. And even a fingerprint on blood is more
S2: likely to be smeared, or certainly not a definite definitive.
S2: There's my fingerprint. I've put it down and lifted it up.
S3: Yeah. And even a fingerprint in blood is an example.
S3: There are different types of ways that that can happen.
S3: You can have a fingerprint in blood where there's a
S3: blood puddle on a surface and you put it in there,
S3: depending on whether it's dry, whether it's still wet, that
S3: fingerprint might be removed. We can have it where we
S3: deposit something and we deposit our finger first and then
S3: blood goes through that. So that's a fingerprint under blood.
S3: And then there's fingerprints in blood where we touch a surface.
S3: Get some blood transfer to the surface of our fingers
S3: and then touch another surface on top.
S2: That would be the most ideal I think.
S4: Yeah.
S3: And because and then they become visible prints for us
S3: because we would be able to see them with the
S3: naked eye. We're not we don't need to use methods
S3: like powdering to see them. If we want to enhance contrast,
S3: we might use special blood enhancing reagents that will again
S3: give us a better chance at recovering an identifiable finger mark.
S3: But we should be able to see them. And again,
S3: that helps us understand the events that led up to
S3: the crime, because in that particular instance, somebody has touched blood.
S3: There has to have been blood there for them to.
S4: Touch and.
S2: Identify whose blood that was.
S3: Yep. And we can do, you know, DNA or blood
S3: screening to find out whose blood that was. Is it
S3: the victim? Is it the suspect? And then we can
S3: use those traces to recreate or understand the events that occurred.
S2: So what is new in fingerprint analysis? Do you see
S2: it as something that's stagnant, or is there something that
S2: is evolving scientifically to improve, being able to detect and
S2: lift and collect evidence that's of value?
S3: Um, so while we might think that it's an old
S3: school technique, it has been around since the early 1900s.
S3: In fact, in New South Wales in 1904, we were
S3: one of the first police jurisdictions to use fingerprint identification.
S3: So it's very well established how a lot of our
S3: methods have come about is through other fields of science
S3: or other avenues. So in fact, one of the methods
S3: that we use. It's called physical developer actually came out
S3: of photographic development. So when the police were developing their
S3: crime scene photos in the dark rooms, they were finding
S3: that if they handled certain pieces of paper that they
S3: were using to develop the photos, they would also recover
S3: their fingerprints as well as develop the photo. So a
S3: lot of our methods have come out of, you know, either. Biology,
S3: chemistry or other areas. And because we we found that
S3: they work we we will use them. So fingerprint research
S3: now it's moved into two main areas. So the first
S3: area is around identification. So this is where we will
S3: have trained fingerprint experts trying to understand. How they identify
S3: an individual, what's their thought processes, as well as the
S3: algorithms that we use. When we recover a print we
S3: might upload it to, we would call it an alias.
S3: So the Australian Fingerprint Identification System, to work on better algorithms,
S3: to be more confident with.
S2: How many points of identification, things like how many similarities.
S4: Yeah.
S3: Yeah. So and also what are the elements that factor
S3: into an expert making a decision as to whether it's
S3: identifiable or not? So you mentioned the number of points
S3: in a fingerprint. A lot of countries have moved away
S3: from trying to reach. So in some jurisdictions they will
S3: say if there are 12 points of identification then that's
S3: a they're fairly confident that that is a match. But
S3: now most countries in the world try to contextualize that information.
S3: Or just because we if you try to get 12,
S3: you're trying to assure an outcome when that outcome may
S3: not be. Accurate or appropriate given the evidence that you.
S4: Have on.
S2: CSI. We've always seen them superimpose.
S4: That classic one. Yeah. And then the.
S3: Green matches up and yeah, it looks great for TV,
S3: but not necessarily a good outcome for us. So the
S3: identification side is one side and then the other side
S3: is around detection. So ultimately the goal when we are
S3: trying to develop or detect a fingerprint, we are trying
S3: to get the best possible image or the best possible
S3: developed mark, because the better the mark that we have developed,
S3: the more likely that we'll be able to more accurately
S3: and confidently identify a person based on their fingerprint. And
S3: so the way that we do that is through new
S3: techniques or new methods. Um, so this might be using
S3: new technologies or new types of fluorescent powders, uh, new
S3: types of chemical detection methods. But then the other side
S3: is trying to understand and the fingerprint chemistry itself, so
S3: that when we do want to come up with a
S3: new method, what are we actually targeting? How does it
S3: work and how can we inform better practice moving forward
S3: by understanding what we're trying to detect.
S2: And then to use that you need to do multiple
S2: studies have peer review. It's not just a eureka moment.
S3: No. Exactly. Uh, quite a while ago, forensic science was
S3: brought into put under the spotlight through two reports from
S3: the US. So there was the National Academy of Sciences
S3: report in 2009 and the Pcast report in 2016. And
S3: in both of those reports, it really highlighted that in
S3: a number of forensic disciplines, there was a lack of
S3: scientific underpinning to the work that was going on, and
S3: that particular types of evidence should not be used in
S3: a court of law without fundamental studies to underpin the
S3: decisions or the outcomes that they were making. So an
S3: area was in bite marks, for instance, so that one,
S3: as a forensic discipline, has been told to go back
S3: to the lab and confirm what you've said is gospel
S3: is is appropriate and with some scientific studies. And so
S3: fingerprints didn't have the same degree of spotlight on them.
S3: But it's always important that we are able to stand
S3: by what we do, how we do it, and why
S3: we do it. And the way that we do that
S3: is through scientific research and peer reviewed studies.
S2: In terms of fingerprints, it's the biggest thing that people
S2: talk about. No one has the same two fingerprints. And
S2: I'm always asked by people, but what about identical twins?
S2: Would you like to finally address that one, please?
S4: I would.
S3: Love to. Um, so identical twins, when we talk about fingerprints,
S3: there are two levels of how we would identify somebody.
S3: The first is what we would call the general pattern.
S3: So this is the pattern that we can see on
S3: the surface of our fingers. And there are three main
S3: types of these general patterns. There are what we call whorls.
S3: And these look like little circles with larger circles coming
S3: from the center. There are loops where we have the
S3: fingerprint ridges coming from one side of our finger. They
S3: get close to the center, do a U-turn and come
S3: out the same side. And then we have arches, and
S3: this is where the ridges will start. On one side
S3: of our finger, hit a little bit of a speed
S3: bump and continue out to the opposite side of the finger.
S3: Now these general fingerprint patterns are passed down by genetics,
S3: so identical twins may have the same type of pattern
S3: on the same fingers as each other. It's the same
S3: as if your brother and sister. You might also find
S3: if you look at your your fingers, you might have
S3: the same. I've got a loop on my thumb, you've
S3: got a loop on your thumb. And so that's a
S3: way that we can classify people or group people into
S3: certain areas and exclude people from investigations. If we recover
S3: a well at a crime scene and our particular suspect
S3: only has loops, well, we can exclude them from further
S3: investigation without going through a full identification process. But what
S3: we use to identify people is that while that general
S3: pattern is one of those three categories, there's actually smaller
S3: minute details that make up this fingerprint pattern. And we
S3: call it fingerprint minutiae. Now, why these are very individualizing
S3: or why we can say with some degree of confidence
S3: that we can identify a person with them, is that
S3: they're actually form randomly. So at the ninth to 10th
S3: week of gestation, as our fingers begin to form at
S3: that point, they're not fingers, they're the shoulder pads. And.
S3: When I begin to form, we will be moving around
S3: in the womb and there will be some random interactions
S3: with the inside of the womb with ourselves. Or if
S3: you have an identical twin, your twin next to you.
S3: And it's the random pressures as your fingers are developing
S3: that create these imperfections on the surface of the volar pads.
S2: So it's not blood supply.
S3: Yeah, no, it's to do with how they move around.
S3: And and it's these random imperfections that create these minutia
S3: that make people, for want of a better term, unique.
S3: Even if we cut ourselves or if we, you know,
S3: fall over and scrape our hands, the fingerprint ridges will
S3: grow back in their original, original patterns if we want
S3: to cause permanent damage. We've got to cut several millimeters
S3: deep into the skin.
S2: That's incredible. So in terms of gestation, a premature bulb
S2: may not have fingerprints evident.
S3: It's very early on. So around that ninth to 10th
S3: week of gestation is when that's starting to form. Yeah.
S3: And so the information will be there by about week 12.
S3: And then it stays that way. And so your fingerprints
S3: will stay the same from when you are born all
S3: the way until you pass away. They'll get bigger because
S3: your fingers will grow over time, but the pattern will
S3: remain the same.
S2: So if you have familial patterns, we've heard about familial
S2: DNA linking people to crime scenes. Is it possible in
S2: the future that you could actually link familial fingerprints?
S3: Uh, so that's not necessarily something that you could do.
S3: So while the genetic information will give you that general pattern,
S3: as I mentioned, there's only at most eight of these
S3: general patterns. And so it's not enough information to say
S3: with confidence that we could identify a particular person or
S3: even group them into a familial sort of similarities. Yeah,
S3: there are similarities, but yeah, there just isn't enough information
S3: at that general level to say with a degree of
S3: confidence that that person belongs to that family, because you
S3: can go down the street and there'll be people with
S3: loops and whorls all on the same fingers that you have,
S3: and they won't be related to you.
S2: Does hand sanitizer remove fingerprints of objects?
S3: Uh, yeah, that's a very interesting question. And in a
S3: post-Covid world, it was part of our daily life, always
S3: hand sanitizing.
S4: And it was it is for some of us. Exactly.
S3: Uh, it's a question that we had actually before the pandemic. Uh,
S3: and so we conducted an experiment to see whether different
S3: types of hand sanitizers would impact the developed fingerprint, because
S3: what we're targeting is often chemical residues. And depending if
S3: we have a alcoholic non-alcoholic, the techniques we use can
S3: be quite sensitive. So introducing something else might dilute or
S3: potentially damage the fingerprint. So through our work, we took
S3: some non-alcoholic hand sanitizers and some alcoholic hand sanitizers and
S3: compared uh, we got them to apply the hand sanitizer
S3: deposit fingerprints after a certain period of time and then
S3: develop them with a range of techniques. And what we
S3: actually found was that hand sanitizer has no negative impact
S3: on developed fingerprints. And in fact, non-alcoholic hand sanitizers will
S3: actually improve the development for a number of the techniques
S3: that we have, and it will actually make it easier
S3: for us to recover fingerprints on certain surfaces.
S2: Well. That solved. Yeah.
S3: Myth. Busted.
S2: Myth. Busted. Awesome. Thank you, Scott, so much for joining
S2: us today. This has been so fascinating. And fingerprints, everybody
S2: seems they know everything about them because I've seen a
S2: crime show once and they know they go back to
S2: another century. But I just think applying them and learning
S2: how you further researching and the science is evolving is fascinating.
S2: So thank you so much for joining us today.
S3: My pleasure. It was great to be here. Thank you.
S2: Crime Insider's Forensics is a listener. Original production. It's hosted
S2: by me, Catherine Fox, and is produced by Ed Gordon.
S2: Sound Design and imaging is by Link Kelly.