A listener production.
Welcome to Crime Insider's forensics. For those joining us for the first time. My name's Catherine Fox. I'm a former GP, crime author and screenwriter. I'm enthralled by forensics and have spent thousands of hours researching for books and screenplays. So I thought, why not turn my research into a podcast? Every week you'll be joining me in discovering how forensic science is helping solve high profile crimes in Australia and
around the world. This week how CCTV footage can lead to convictions, but also miscarriages of justice.
Unless you can prove it scientifically, you can't really make that claim. And that was the fallacy of individualization. If you can't prove it scientifically, don't use it.
Professor Glenn Porter is an expert in the field of forensic photography. He spent decades taking photos, analyzing them and presenting them as evidence in court.
So it's very much a filmic visual narrative that crime scene operatives work on.
It's easy to think that video and photographic evidence is the smoking gun and the slam dunk for a conviction, but it's actually far more complicated and not as clear cut as you might think. You'll hear from Glenn about how photos can be extremely helpful, but also can sometimes hinder a case for the prosecution. Glenn's taking us back to a high profile double murder.
Peter Johnson was accused of murdering a couple at Cadi. The police facts allege that Mr. Johnson tortured these two people to get their Pin number, and then went around ATMs extracting money. Now, there was an ATM in Windsor, in western New South Wales, where the CCTV captured what police allege. Mr. Johnson taking the money out. But the quality of the CCTV was quite poor and you could see by the footage that Mr. Johnson was aware that there was a camera there. He did what I would
call a recce. He walked past and noticed that the camera was there. So when he was extracting the money, he held up what looked like a white handkerchief or something like that over his face, so his face couldn't be identified. So police had the details of the ATM, obviously the account of the deceased, um, there was a slight time difference between the ATM and the CCTV timestamp, but that's that's fairly normal. The technology never lines up all the time, but the couple were dead in their
home at that time that the money was extracted. You saw this person extracting the money. The police went and interviewed two people, his ex-wife and a friend of Mr. Johnson, and showed them the CCTV footage, which they were able to then identify Mr. Johnson through that video footage or
the CCTV footage. When it came to Mr. Johnson's trial, I gave evidence for for the defence on the issues that may occur because in both of the statements and their oral evidence, they said they couldn't identify Mr. Johnson from his face because he was covering his face and it was fairly grainy, fairly poor quality. But they could recognise or identify Mr. Johnson through the way he walked.
Now the problem I had with that, from an evidential perspective, I'm I'm not doubting what they claim, but the issue there from a technical perspective, was that the CCTV was shot around two frames a second, which results in a very jagged, animated type of motion. It's certainly not a natural motion, which is around 30 frames per second. So I was tasked to explain to the court how this
could be misleading. The motion isn't a natural motion, so to make some form of recognition or identification could be dangerous. I gave my evidence and Judge Anthony Wheely very good. Supreme Court judge asked me a question. He said. So, doctor Porter, are you referring to a situation similar to a Charlie Chaplin film?
The silent movies.
The silent movies where the movement is quite animated, jerky and not natural?
Well, that's probably because back then the silent films were recorded at about 16 to 18 frames per second. And I think for people to understand, it's almost like one of those flip books. So we used to draw as kids, you know, a whole thing of papers in a, in a book, in a corner, and then you can get your own little cartoon going. So it's easy to then understand in that context why this gentleman's gait would have appeared quite odd.
And that distortion, I don't know how much it would affect their ability to make that judgment. That's that's not my call. But what was interesting, too, is, uh, Judge Whaley also instructed the jury, um, as a result of another Supreme Court matter, uh, Tang, he instructed the jury that the evidence given by the two witnesses is not identification evidence, but recognition evidence that they recognize Mr. Johnson on the video.
The difference between thinking they recognize and identifying correctly. There seems to be a very big gap between the two. Just as a layperson.
Yes. And there's a couple of distinctions. I mean, in facial identification, there's a distinction between facial recognition software, which enables a search of a database, and it gets to a what they call a recognized level. But to go the step to identification, it needs a forensic expert that's trained in facial identification to be able to make that
claim a little bit like a fingerprint. They were used the automatic fingerprint identification system, Aphis or Nifrs, and to do a search of the fingerprint that they might have found in the crime scene, the AI or the computer technology can do a search of thousands in the database, but it's actually the forensic examiner that actually takes it to the identification level. And that's that's a system similar to forensic imaging. And there's been quite a bit of
work done from. Universities around the world, in psychology departments, around people's ability to recognize people in images, and even in poor quality CCTV or poor quality video. And the results are quite consistent. The psychologists split it up into two categories familiar and unfamiliar faces. So if you know somebody even with poor quality CCTV, the accuracy is quite high. But if it's an unknown, an unfamiliar face, the error
rate goes up quite significantly, up around 3,040%. So it's an interesting part of our innate ability to recognize people when we see them. Familiar faces. We do a pretty good job at recognizing them in images, even if they're poor quality.
One of the interesting things, though, is comparing to a fingerprint. There's only a finite number of whorls, loops, things that they can find in combination. Surely in a human face there are so many variables length, distance, um, depth of muscle, fat, tissue. And then you have possible cosmetic interventions as well. Is a face like as unique as a fingerprint?
Well, the difference major difference between face and fingerprint is that faces change. Fingerprints don't. So weight gain, weight loss, cosmetic surgery as you mentioned, age. That's one of the things that's made facial identification quite difficult that it's not consistent. You need a known source and exemplar to make that comparison. And that exemplar is obviously done sometime in the past. So depending upon how far in the past it was
may affect the the accuracy. Martin Evison in 2014 wrote a brilliant paper called The Third Forensics, and he suggested that forensic identification is entering its third phase. So fingerprints being the first, DNA being the second method, and faces identification was going to be the third forensic identifier, but it just hasn't played out that that way.
You mentioned the database with fingerprints. Facial databases. Do they help you in terms of helping to identify a person, in terms of the likelihood that these facial features are consistent with this? Person in this photograph.
Yeah. So there are some systems out there that the Australian government are now using for facial identification. And we see it now on our mobile phones when we sign deeds and contracts, you can there, there are verification sort of processes that are using the face as a, as a form of verification based on your passport photographs or your license photograph. So that technology certainly coming to play.
That's facial recognition isn't it.
Facial recognition. Yeah. Not identification from a forensic perspective. Yeah. But but certainly the facial recognition is is playing a part with facial databases because we, we've been in New South Wales and other states, we've been collecting biometric data from our driver's licenses for 15, 20 years now. It's been quite a while since photo ID has been used in our driver's licenses. Those authorities, government authorities have been
collecting that. Same with our passport. Our passport now has biometric information. A passport photograph has biometric information. So the state actually has as a resource quite a lot of people's faces in databases. How is the state going to use that. They've got some legislation at the moment that
allows organisations to use it in those software applications. I just had a one of my PhD students who finished a research project looking at whether the facial databases and the facial recognition software, when you get poor quality CCTV where you can't really see facial detail. She tested whether forensic artists could be a transition between the CCTV of
poor quality and the facial recognition software. So an artist sketch off the images and then the facial database can search the actual line drawing or the sketch, and she come up with some very interesting results that said that, yes, the technology can recognize, um, drawings. And in some aspects
they were better than poor quality CCTV photographs. The artists are outperformed in in some areas, particularly areas of really bad angles when there was a sharp angle, not a normal frontal view, which is, um, straight on which I'm looking at the camera. Now, that's a normal frontal view, but any side angles or uh, high angles, which CCTV often is high, um, the, the artists actually outperformed in
some instances than the photograph. So that was an interesting experiment that Vanessa, uh, gained a PhD out of.
In terms of what can people do if there are so many images out there? And I just think how many selfies are being taken by criminals and non criminals every single day. There's got to be millions and millions of of photographs taken and uploaded. So potentially there's a massive database, a private companies utilizing that database.
Yeah, it's a bit. It's. There is some legislation around where private enterprise can use software from the federal government, and they can access certain elements, but they don't access the database, but they can apply for a recognition search from different faces. I'm not familiar with the 100% with the legislation, but this is something that's come over the last couple of years. It's going to be obviously more prominent as we move into the AI tool of technology,
I would imagine. I also had an honor student who's just finished an ex police officer, Tony Caledon, and his career was working in the police, in the BCI and also in intelligence and then privately over in private security before he retired. So he's got a sort of a background on both of those. And what he found in his research is these notion of fusion centers going to occur where surveillance of the of areas are going to
be black box. So with AI being able to interpret activity rather than if you can imagine a security officer sitting in front of, you know, 200 screens, the the amount of detail becomes kind of white noise and detecting things that are happening is not very easily. Well, in fusion centers, they're all blacked out. Sort of uses a simple,
oversimplified analogy. They're all blacked out until the AI detects some suspicious behavior, then it becomes visible, and then the security agency can then may make a decision on the action.
So it's an interesting concept that Tony kind of discovered that with fusion centers, you're going to get more surveillance of the civilians or of the citizens, but more privacy, which is a bit, you know, sounds contradictory, but, um, there's some protection of the privacy because it's all black box until you see someone in a car park looking into car windows to see if there's anything you know in there to steal the. I would pick that up as suspicious activity and then turn on and alert the
security agency to. Then they can make a decision on what that action is. So the technology is going to get very clever. Um, but I think it's good in one way that there thinking about the privacy because we don't want an over surveillance state. I don't think most people would want that. But this fusion center technology may have our interest in in heart, I guess, around privacy. It'd be interesting to see how it pans out over the next ten, 15 years.
Well, we've also seen deepfake videos, and this is obviously a very divisive thing that you can, um, if you have the technology and the ability you can. Completely alter someone's face in a video and replace it with someone else's. For example, at the recent international forensic conference, one of
the forensic scientists had Obama, President Obama. Actually introducing her, and everyone initially was like, oh, and then 11 or 12 seconds into it, the mouth didn't sync with the dialogue, and so we all realized that it was a deep fake. But just initially there was a room full of forensic experts who were, oh my gosh, is that actually a bummer introducing her? And that was the whole point. If you could even convince a roomful of one of 1500 forensic experts how easy it is to fool the public.
That is very, very worrying. And, you know, can you trust anything in imaging? That's that's where we might go. But the filmmaker, Errol Morris, uh, has published a book called Believing Is Seeing. And I've got a quote from Morris book. It says photographs provide evidence, but no shortcut to reality. It is often said that seeing is believing. But what we do not form our beliefs on the basis of what we see. Rather, what we see is often determined by our beliefs. Believing is seeing, not the
other way around. It sort of highlights the ambiguity sometimes of imaging as evidence. It's what we want to, uh, believing is seeing the imagery, the fake, the deep fake, or you know, that it's Obama and you know that he's talking. So you often would come to the belief that that's Obama talking.
In terms of having a suspect in custody. We all know about mug shots. Profiles front on and each profile can vary too, so I gather they take each side. Do the police have a right to actually try and photograph from the same perspective, for example, as the ATM captured, to try and then superimpose the accused face onto the evidence that they have and see if that matches.
We've seen this in some cases where anatomists have superimposed faces onto forensically obtain images. It's it's dangerous. Um. Superimposition can. Hide something as well as show something. So again, it can really superimposition can really trick people's brains. So it's I'm not much of a fan of it. This technology
came out with identification of, of skeletal remains. So they would get a skull and get a photograph of the person or the deceased who they think it is, and then they would superimpose that image onto the skeletal, onto the skull, and match up certain anatomical points of the eye sockets and the teeth and, and those type of things to try to identify the body. And this is a technique designed before DNA. So DNA is obviously the
the premium method for identification now. But if there's no DNA to match it to or no maternal DNA with mitochondrial DNA, this technique I guess, is still valid. If you talk to a fingerprint expert. What they don't do is superimposition, fingerprints, and there's a good reason for it because of the.
Distortion they do on telly all the time.
Yeah, they do a lot of things on tele. Um, it can be more misleading than give information so side by side, like for like combination is by a forensic expert is the method of choice rather than superimposition. It's too difficult. But image perspective which can change the face quite a lot. Um and image perspective is. The spice, how three dimensional objects are now recorded into two dimensional. And basically, if you got and you'll see this on a lot of selfies, you know, close up any close
up photographs of people's faces. The image perspective is quite deep. So you might notice that, you know, the person's nose seems exaggerated in a very close up photograph. The further you move away, the flatter the perspective comes. And I've measured about four meters. After four meters it becomes fairly stable. So fashion photographers use this quite a lot as well.
This technique, in the sense that, you know, when you're using people that have this beautiful proportionality of their face and that's what makes them pretty and attractive and models what you want to do is a fashion photographer or a beauty photographer is capture that natural beauty. The approach to maintaining that natural proportion and beauty is usually shot on a long focal length lens at a distance, so so that those proportions and parts of the face are
maintained naturally. As soon as you start bringing the camera in closer, the proportions of the face, particularly the nose being closer to the camera, will start to exaggerate and those proportions must be disrupted. So part of the problem with superimposition is that you don't often know the distance between when that CCTV camera you can go and measure it, which I've done at crime scenes as well. But then you have to try to reproduce it. And there's a
lot of, um, difficulties with trying that approach. It's not impossible, but superimposition is is certainly not the way to go with facial identification. A side by side like for like is is the method if it's an infrared versus a color image, that could be problematic because of the differences. They should be roughly the same angle, normal font size is the perfect angle, of course, but often that's not the case in surveillance photography.
What about ease in terms of uniqueness? How reliable is analysis of ease and comparison in photo?
The term uniqueness is being a bit of a dirty word in forensics over the last few years, because we've always claimed that fingerprints are unique. But from a scientific position, we can't prove that.
Unless you've fingerprinted every single person who's ever lived on the planet, you.
Can model it. The US government tried to model. Model fingerprint? Statistically, DNA does it through likelihood ratios. You know, to say that 1 in 20,000,000 chance of someone having the same DNA. So it can be modeled statistically. But uniqueness is something that we don't like to sort of, uh, say, well, we can say that they, they match or they have similar characteristics, um, as to satisfy a match or whatever, but not the concepts of uniqueness. So like fingerprints, there's
a claim that is, ah, unique. But we can't prove that scientifically. And, you know, when you're comparing side by side is which is what we can do, you can say that there are a lot of strong anatomical similarities between the two ears, and the likelihood of it being the same is fairly high, but we we don't use the word uniqueness anymore. Um, that's something we've, we've got over it took fingerprinting, uh, bureaus quite a, quite a while to go away from that. And I think they
may still not believe that fingerprints can't be proven. You know, um, Michael Sachs, uh, us sociologists has written really well on this, uh, around the, the fallacy of uniqueness and that, you know, if we're using scientific methods within our forensic analysis, you can't then come up with this qualitative claim that every fingerprints, unique or every is unique unless you can prove it scientifically, you can't really make that claim. And that was the
fallacy of individualization. If you can't prove it scientifically, don't use it.
With all these variables light, angles, perspectives, distance. How on earth is anyone actually identified by a photograph? Beyond all reasonable doubt.
It seems you know, as much as I mentioned Martin Stevenson's paper, the third forensics, it looked like, you know, back in 2014 that this was going to be a revelation, a new way of identifying people with the predominant amount of imagery in the community, cameras in the community. This is going to be the the next best thing since
DNA and fingerprints, but it just hasn't eventuated. I think the facial recognition software and the tools that might be used in the private sector and the verification of identity, I think that's that's where facial recognition is going to really play a part. But I'm not sure whether in a forensic situation that this form of identification evidence is going to resonate like the, like the fingerprints and DNA. I know the AFP's facial team, the last time I
spoke with them, they hadn't gone to court. But they're working very hard in developing standards and developing training for their people. They're doing a very good job. But I think our initial thinking that being able to identify from it because it is in some way a trace like fingerprints and DNA left at the scene. But it's not
a real direct trace. It's a visual trace. So there is some ambiguities and or differences between, I think that biological trace of a fingerprint or DNA versus a biological trace from a camera. There are just some, some complexities that it's just not made it as easy as what we thought it was. You know, if we time traveled, uh, 50 years, not even 50 years, probably 20 years, 25 years and say to detect these right in the modern you, you're going to have this resource where every crime is
going to be recorded by a camera. Do you think they'll need detectives? And okay, well, of course not, because there it is. But it hasn't eventuated. Um, identifying people with difficult.
It sounds to me like photographs are actually circumstantial evidence as opposed to definitive evidence. And I would ask, and we actually giving defense teams more to pick holes in by bringing photography and CCTV into it.
That's a very important element, because what I've seen over the, in my experience, is the misuse of photographs as well. And this is this is a problem. I remember being in a biometric conference and I was on invited on as a panel of experts and, um, a guy I have a lot of respect for. Richard Brooke from the FBI was on that panel as well. And the question was asked of Richard. Richard was using a lot of facial identification in, um, in the FBI. Uh, the famous
case that he worked on was the Afghan girl. I don't know whether you're familiar with Afghan girl, with, uh, Stephen McCurry. Um, National Geographic, the green eyes. The green eyes. Yeah. The green eye. Beautiful Afghan. Beautiful. Yeah, yeah. Absolutely stunning. They went back a few years later and tried to identify it. And I believe the FBI certainly made the identification.
But it was asked of the panel, particularly Richard, of um, so what happens if you can't identify them, you know, so you've got a mugshot and exemplar photographed a source that you have known, known and known identity. And you've got a, a still of a, of a face from CCTV or ATM or a mobile phone, but the experts just can't identify it because, you know, maybe the quality isn't there or just it just you just can't identify it.
What do you do? And he said, that's simple. We just put the two photographs together, paste them on a board and give them to the jury. And I sort of went, what do you do? What I said, so here you are, the FBI, who have all these trained science scientists and forensic experts trained in facial identification. They can't make the identification. But what you're asking the jury is to make that identification for you, because you can't. That's outrageous. That's that's biasing the evidence in a, in
a in a very big way. And a good friend of mine, Gary Edmund from the unionist South Wales, he's position that he I've heard him say quite often is that particularly with fingerprints fingers fingerprints do the same. Fingerprint experts will have the exemplar and the fingerprint and the points of identification. Give that to the jury and they will see, you know, ten or 20 or 15 points of identification. The fingerprints. I don't have too much of
a problem with that. But. But Professor Edmond suggests that. Well, if you've got the expert there, you don't need to show them that photographic evidence. And I think he's got a really strong point there that whether showing that sort of visual aspect to the jury, does it better inform them or is it influencing them in a wrong way? Another, um, encounter I had, it was with the New South Wales Police.
I was asked by the chief scientists at the time to do a review of the forensic forensic photography, a forensic imaging unit in the New South Wales Police. And I did that with another AFP senior AFP officer. And we were shown around the the unit and we went to this, uh, one room where they had a poster and there was a CCTV photograph of two people holding up another two people in a park. I think it was in King's Cross. So then they had, uh, so
just try to visualise this poster. So this big image in the middle was the CCTV image of the incident, a still image. There was then close ups of each person's head on the left hand side of the right hand side. Sorry of the poster. Then on the other opposite side of the poster was the two mug shots of the people. And I said, well, so what's this poster for? They said, oh, it's for court. Uh, identification of the people. Oh, you say you've identified them? Oh, no, no, no,
we can't do that. Um, but we show them these posters so that the jury can, you know, uh, correlate between the the two close ups of the faces. So this is an example of issues I've come across where it's treating the jury as, uh, pseudo experts by showing them images. And we all believe we're very visually literate. We're a community that embellishes images all in everything we do. Even, you know, we're doing that now. We're recording this on
on a camera, this conversation. So everything we do just just about is recorded in some visual form. I have some concerns when photographs are misrepresented to a jury in a seemingly unbiased, unaltered way for them to make up their mind. So using photographs, I think can be quite dangerous.
And there's no filter with this at the moment in the criminal justice system, the judges, uh, that I've come across, uh, believe that the more information you can give the jury, the better the jury are to make the right decision. I certainly agree with that. But whether images can help or hinder the truth is something that's a bit concerning when it comes to visual evidence in criminal cases.
There was a case that involved Larry David's show, Curb Your Enthusiasm, and the role that that played in a criminal trial. Can you go through that for us?
Sure. Um, I wrote about it in my PhD thesis many years ago, but it's, um, it's a bit of a reverse, uh, identification. There was a gang murder, and one of the witnesses to that gang murder was actually murdered herself. And the accused of the original murder trial. His brother was charged with her murder, and he claimed that it couldn't have been him because he was at the baseball with his daughter. And he produced the seating stubs to the police. And they said, well, you could
have got this off anyone. They tried to look it up with the CCTV cameras of the stadium, and they saw where his seat was, and they tried to enlarge it, but it was just too it just didn't allow definition that they could identify him sitting there with his daughter. But for some, uh, strange reason, Larry David was shooting, I think, Curb Your Enthusiasm show. And there was the accused in the background, sitting in his seat.
With a good quality.
Film. Yeah, broadcast quality film. And they use that. And of course, they got, um, uh, statements off the producers of the time and the and the time and date stamps on the, on the video. Um, and his alibi then was confirmed that he was at the baseball through the happened chance of being in the background of Larry David's show. So quite a quite an interesting.
High definition.
In high definition. Yeah, yeah. And he was telling the truth.
So it can actually be used to exonerate.
It can be used to exonerate. Absolutely. Any forensic evidence is about the first of all, trying to exonerate innocent people and secondly, trying to, uh, to convict or use to in the conviction of perpetrators of crime. But the primary objective is always to try to eliminate first, not not identify. Being an academic in forensic science at Western Sydney University for several years, being one of the founding
academics or the founding academic there. For that course, we built a crime scene facility with the New South Wales Police, where students would go through and actually process scenes of crime. Forensic photography is more of the specialisation, the the enhancement of the of the evidence. Uh, the understanding reading of
how vision works and how it how it affects the interpretation. Um, I think that's more about forensic crime scene photography really is more about recording in a document style, um, in a vernacular kind of photography, how the scene was found, items of evidence, murder, weapons, shoe marks and so forth. There are particular ways that they need to be photographed, but what a crime scene officer does in the processing of a scene is document. And they would they would
document in images, usually video or still photography. They would write contemporaneous notes on where they saw things and how they found it, and also sketching, which is another visual, cultural sort of aspect to understanding crime scenes. So crime scene investigators would do those, those three things. They would also collect the evidence, but say shoe marks and fingerprints, items that are going to be analyzed. By other forensic experts need to be taken in a particular way so
that distortion and artifacts are eliminated. And that's where forensic photography training has to occur with crime scene investigators. So they do do some, I guess, forensic photography on site when it comes to recording, documenting those types of evidence. But in a whole it's more around just recording the site as it's found and the critical elements of the site. They sort of work in a photo narrative form more
so than anything, and they would use filmic techniques. So for instance, if there was a shoe mark in blood, they would photograph it using a style of photography, but in a way that that a filmmaker would approach it. So you do what we call an establishing shot. So you do a wide shot to show the location of the shoe mark in blood, and then you do a close up shot, which would be the forensic kind of where you would put a scale down. You would make
sure that it's perpendicular to the subject. You would use lighting to show that the, the maximum detail of the, of the shoe mark. So it's very much a filmic kind of visual narrative that crime scene operatives work on in combination with their contemporaneous notes. And they use tools like markers, evidence markers to show and relate the photographs in the sketch to the contemporaneous notes. That's all a
way of communicating a bloody shoe mark. That could be a item I found in the the lounge room or whatever, but that marker that's placed next to the the shoe mark, that item of evidence is only there really, so that the contemporaneous notes and the sketches and the photographs all tie in in a communicative way. And you.
Can get a sense of scale and you can.
Get a sense of scale. So we use linear scales to do that. Um, and, and, and all sorts of things. Yeah. And now with drones, you know, you can get aerial shots as well. Um, New South Wales Police, we were very big on using photogrammetry as well, where they would go in and use stereo cameras and record it, particularly for, uh, motor vehicle accidents particularly, and then reproduce that accurately. So measurements can be taken from their line drawings very similar
to an old plan of a building. It's they sort of they can draw scenes in that sort of line sketch, but it's to scale and things can be measured.
We've actually seen lots of visual illusions, and there's been so much fighting on the internet about, for example, the dress there was blue and gold and whatever people would argue to the death that they were totally different colours from what someone else was seeing. Can you give us an example of another visual illusion that people can actually understand? How our minds can be tricked, even though we're convinced otherwise?
Yeah, there's lots of examples, Cathy. Um, I give a lecture in forensic photography or forensic criminology subject that I teach here at the university on how to interpret images. And basically what I'm trying to show the students is the ambiguity, how ambiguous a lot of the the vision is.
An example is a horse race, uh, photo finish. You you would believe that they're in different places of the track, but in actual fact, the way that it's recorded through a slot, the horses are at the same location, but at different time. So in this type of recording, the variation is the time, not the distance, but our interpretation is the distance because we see a horse in front and a horse behind that the horse in in the crossing. The line first is though is in front of the
horse coming second. But in actual fact, the photo, the imagery is all taken at the same location. The difference? There is time. But another great example is a checkerboard example by, um, a researcher called Edward Allison, who uses a visual anomaly where there's a if you can vision a black and white checkerboard or a chessboard like, well, like we all know, and there's a green cylinder sitting on the, uh, checkerboard casting a shadow over the checkerboard.
And there are two, uh, squares that Alderson identifies, square A and square B, and the question is, is, is the tone of A and B square A and B the same or different? Now, unlike the dress that has people, C perceive the colors differently in this experiment, everyone that I'm aware of sees the two squares as different tones, blatantly different tones, and they would believe and swear that
they are different tones. But if you were to isolate everything else and just look at those two squares like I do in my class, you'll see that that they're exactly the same tone of gray. I've even use Photoshop and measured the A square and the B square, and I get the same RGB value, uh, in both. So empirically, I've also proven that it's the same tonal range, but if you see it, uh, you would believe that a square A and square B is absolutely different tonality. But
the reality is it's the same. And I'll go back to the Errol Morris quote, believing is seeing. It's not the other way around. You believe that it's different, but the facts are they're the same.
I think my brain is just absolutely mashed up now because I thought photographs were definitive, and now I'm actually thinking it's all an illusion. Thank you so much, Glenn, for actually getting us thinking about photographs and reliability and evidence and facial recognition versus identification. It is so complicated. Thanks very much for joining us and explaining all of that today.
You most welcome, Kathy anytime.
Crime Insider's Forensics is a listener. Original production. It's hosted by me, Catherine Fox, and is produced by Ed Gordon. Sound Design and imaging is by Link Kelly.