Implications for policing & cold cases

38:00involving electro deposition. Um the paper is out in forensic chemistry by Mayouth University in Ireland. The fingerprints are typically destroyed whenever a firearm discharges, right? Because you have stuff like 500° C, pressures of 50,000 lbs per square in. Um and this method exploits some organic residue >> that's that remains even after all of this stress. and it like amplifies that organic residue to create a fingerprint. All right. And it's it's very cool that the the electrochemical techniques that they're using to do this. Okay. And the significance is as I was saying, right, the print on the casing >> links individuals to the act of loading

38:42the gun. And before we really only have the possession of the firearm, but it could somebody else could have done it. Somebody could have taken the firearm and done something. >> Um. >> Yep. And the prevailing consensus is the violent process of actually firing a bullet would destroy the fingerprint on the casing. >> Right. The the the theory of the case is you're never going to get the fingerprint off of the fired bullet. >> Exactly. Yeah. And it is a pretty violent process, right, of firing I' I've fired a gun only once. I went to a shooting range and it was like one of the crazy craziest exhilarating experiences I've ever had. I've never done it again. Um, so I don't I don't I

39:22had to do a lot of research on how the gun works and the physics of the gun, but this is my twominute summary of of the process. This whole thing happens in under two milliseconds. You've got a casing that has gunpowder >> and then you've got the bullet, which is the projectile in the front. You've got a firing pin, and when you hit the firing pin with the the trigger, that causes a chemical reaction which raises the temperature inside of the casing. all of that gunpowder or whatever goes up in temperature around something like you can you can get as much as 2,000° C and then that's going to expand a lot of air which is going to shoot the gun forward. Okay, that's not the end

40:03though because afterwards you have to take out the casing and replace it with the next one. Right? So there's like a thing that grabs the case, pulls it back, throws it away, and then loads up the next one. Right? M. So all of that stuff is going to mess with the fingerprint that's on the outside because when the bullet is fired, that expansion of the air is also going to first of all it's going to heat up everything. So any organic residue that you have like the proteins or any carbon that's just going to burn up >> burned off. Yeah. then the the casing itself is going to expand into the chamber >> and when it and when you pull it back that friction is going to then again

40:44destroy any residue of a fingerprint that's on the outside. Right? So there's all of these different things that are happening that will completely mess with the fingerprint that's on the outside. Okay. So the recovery relies on some persistence of like a decomposition product that's on the outside. Okay. And what this particular um paper is focusing on is the carbonized ash. So there's going to be some inorganic salts that are left by our sweat and our oils that is going to remain. It's going to get burned up, but the ash is going to remain on the outside. >> There's the the idea being the theory of the case is there's no organic residue that

41:26will be left after the bullet is fired because it's just going to get burned out. >> Yeah. like the proteins, the oils, and the lipids, it's gone. But their hypothesis was there's going to be a little indicator still left >> despite all of that. >> Mhm. Yeah. And and it should be the burned up ash of all of that stuff. >> Of all of that stuff. >> And there should be a little bit left. >> Mhm. >> Right. And if there's even a little bit left, there's a chance. >> You're So you're saying So you're saying there's a chance. >> Exactly. And so And so that's that's what they're doing here. This isn't completely unprecedented. Okay, so in 2008, there was a guy, Dr. John Bond. He came up with a mechanism to actually

42:08figure out these casings. Um, >> there that's crazy that his name is Bond. >> Yeah. Yeah. And it I I I thought it was like part of the Bond when I was reading it because my summary just had Bond and even the the the news articles about this just have Bond and I'm like like James Bond like like this is you know maybe this is one of um Q's >> like weird techniques that he's that he's made but no this is Dr. John Bond and he came up with a way of using really high voltage 2.5 kovts, right? And what you do is you realize that most of these casings are made out of brass. >> Mhm. >> Which is um copper and zinc.

42:48>> Okay. And the zinc and the copper are going to react with the oils on my finger in different ways. >> Okay. >> Okay. So, where the fingerprint was, that's actually going to create a chemical reaction and a corrosion of the zinc part. M >> not the copper part. >> Okay. So, there's going to be different resistance. There's going to be different tiny layer of different metals. And what I'm going to do is subject this casing to really high voltage. >> People are crazy. >> And then put a fine conducting powder on top. And then that powder is going to be attracted to the corrosion sites because that's going to be high more conductive than the rest, right? And then I can I can make a a fingerprint out of that.

43:29>> That's so brilliant. >> It's it's pretty brilliant. So in 2008 this has already happened. This is going one step further further. Okay. Okay. And so the the we've we've identified that we can basically put like current into a a substrate and it will basically reveal this red like this pattern which is the fingerprint we're looking for because the zinc interacts the way itself the metal itself interacted differently with the organic you know residue which is just us touching the outside of the brass bullet casing where he's like let's just pump it and and then it just shows That's so I know that's like a bastard, but that's so >> I think that's pretty cool.

44:10>> That's pretty cool in and of itself. >> Yeah. The the problem is it works on brass because it requires this alloy, right, of copper and zinc. >> Yep. >> Well, now I mean I think there are now casings made out of steel, stainless steel and things like that. It's not going to work because the chemistry is not going to work with the iron and the and the carbon that's in the steel. >> Okay. >> So, what these guys did was use a process called cyclic voltometry. So you start with an electrochemical cell which is a three electrode setup. You've got a working electrode. In this case, this is going to be our brass casing, the thing that we want to actually test on. There's going to be a counter electrode which basically completes the circuit. And then there's a reference electrode that keeps the circuit at a certain

44:50voltage. >> And you've got so so imagine you you take your breast casing, you put it in a chamber with a bunch of electrolyte around it. So chemically conducting water effectively. You attach a electrode lead to it. You have other leads. And now what you can do is start turning on the voltage very gradually. >> Okay? And that's called cyclic voltometry. You turn on the voltage extremely gradually. And what you do is you measure the current. There's going to be a blip in the current. There's going to be a peak in the current. And that corresponds to something called the oxidation potential. Effectively, there's some current that is going to allow a chemical reaction to take place on that surface. Okay. Mhm.

45:33Once you tune it to that peak current, you can keep that current at as low as possible so you you don't make any other weird chemistry that's happening and really tune it to that residue that you want. >> Mhm. >> Right. And this is the ash that's been left over after the the casings come out. Right. Yep. So you're at a low enough voltage >> where you're not destroying any you're not causing anything else to start destroying the ash that's there. You're only tuning it barely to that ash >> ash itself. >> Okay? >> Barely to that ash itself. >> And what ends up happening is you you get these two polymers called E dot and

46:13P dot. It doesn't matter what they are. The the effect the effect is they're polymers that are long chains but still really really small in terms of you know every day but they're but they're like single chemicals >> and what those single chemicals are going to do is when this chemical reaction is happening this oxidation reaction the chemicals are going to get deposited on the ash >> okay >> or actually no sorry they're going to get deposited on the metal and they're going to leave the ash alone >> okay Cuz the ash is going to be insulating. >> I got you. >> I should say that. I should say that again. >> You you you stick the electrode in, you charge up the casing. >> Yes.

46:53>> That's going to have a bunch of carbon ash and residue on it. That ash is going to be insulating compared to the metal. So, the chemicals are going to get deposited on the metal, but leave holes >> where the ash is. >> It's It's like the opposite of the tracer stuff that they put in mice when they're trying to test them to follow it. It's like the opposite imprint of of like that. >> Exactly. Exactly. What's left is what we're looking for. >> Yes. Exactly. And so now we have a way of of actually doing this right now. Why is this better than the 2008 method? >> Okay. Yeah. >> For one, >> I can do this on steel. >> Okay. >> Right. >> I don't need the brass zinc and all that stuff. >> The other is you get a lot higher

47:35resolution on this. Okay. This E doine method consistently yields grade three visualization. I didn't know this about fingerprints. With fingerprints, there's level one pattern, which is the fingerprint itself. The level two pattern is the detail on the ridges. And the level three pattern is within each of our ridges, there's little pores. >> That's crazy. >> Where the the pattern of that pore is also unique, >> okay, >> to each individual. >> Okay. >> Right. And so to really like start getting something that I can admit in court and all this other kind of stuff, it'd be really nice to get level three patterns cuz sometimes level two patterns like let's say you have like

48:16just the edge of someone's fingerprint. Well, that edge could maybe match to somebody else's fingerprint and things like that, but if you have the edge of someone's fingerprint and you have the pattern of the holes, >> that's now extremely hard >> to to match to erroneously. >> Yeah. Yeah. Yeah. >> Right. And so this current method actually lets you resolve those pores with these micro deposits, right? You've got you've got a mechanism to now actually visualize those pores with those electrolyte contacts. And this is from the paper. You can see very clearly the pores and the ridges, right? And this is at tens of microns of resolution. >> That's the other key that's very

48:56different. In the 2008 method from Dr. bond. He used a conductive powder. >> That powder, the size of the powder >> is your >> is bigger than the pores. >> Yeah. That's your limiting factor for resolution. >> Here we're doing single molecule deposition. >> Right. Right. Right. Right. Right. Right. So it makes total sense the this is so I'm just like been out of shape at how clever >> Yeah. >> conceptually like people think about this stuff. >> Yeah. Why don't we put it in a >> and put some electrolytes around it and then we know because we know the other aspects of this chemistry we can just in it right it should this should probably

49:38work >> and then when you do it and and you see you know the example image we just looked at where it's getting the the the level of detail oh sorry not this one but number eight where we now see in the real world that detail difference. >> Yeah. Um I mean like again even as as sort of someone who's maybe not in forensics, you could understand why you would want something with this the level of fidelity on the right versus on the left. >> Yeah. Yeah. Exactly. And then it it's it's pretty awesome. >> It's pretty cool. >> Yeah. Um the other cool thing that they did was actually like so you know your casing goes in Yep. um in order to maintain a uniform electric field around that casing during this electrochemical reaction, they had a customuilt cylindrical chamber that would sort of

50:20make a uniform electric field. >> Okay? >> Because if you put it inside a box, then the edges the edge effects are going to be different and you're not going to get the complete fingerprint around the thing, you know? So now it moves to a place where okay if we want to implement this in industry for each different size of casing we should have different size chambers to actually do this reaction. The other cool thing about this is >> the Dr. Bond method took 2.5 kts. That's not something that I can like hook up to my car battery and like right >> this thing takes less than one.1 volts. So this could be handheld. M you can have basic >> buy the crime fighting units.

51:03>> Yeah. Yeah. Yeah. Yeah. And they you could do it on site. You wouldn't necessarily have to send it to a lab. >> Yes. And then you know with that stuff timing is everything. So So there's a lot of really new stuff that's happening now. Before it actually gets implemented it needs to pass something called the Dobert standard which is the standard that they have in forensics before you can admit something in court. Okay. like DNA testing had to go through this things like that. It relies on testability. You got to have peer review. They already have peer review with this paper. Um you got to figure out what the error rates are among a general population like not just let's say white males but okay, how does

51:45it work with women? How does it work with different races? Things like that. And generally to accept everything, all of these things have to be checked. So that's the next step. It's sort of like the regulatory process or the governing standard for this moving from being something that is interesting and people could utilize but not then have be admissible in court to it being be able being able to be used uh to actually say you know as evidence that someone is the shooter. >> Yeah, exactly. And um one last thing that I want to talk about is the fact that they can actually do old casings as well. They tried to do a fingerprint from a 16-month-old casing and they were actually able to recover a fingerprint

52:25>> which is uh you know so this isn't like just now they could be going back. >> This is okay. >> Yeah. >> Look. >> So >> look >> if you thought you got away I don't know. [laughter] >> Yeah >> that's actually very a very important detail. Yeah, >> because it it kind of you know I think because for example if for all the fans of true crime podcast etc >> with the advent of DNA >> testing a lot of cold cases have affect have been reopened >> and you know people have started to you know >> uh get caught for stuff they did ages ago. >> Uh this is another >> there's another one >> another lever that could unlock a lot of stuff there. I mean there's a lot of recent cases I can think of where this

53:07existing uh would have been I mean me the stallion and had a case with uh that little rapper that I can't remember his name right now who's in jail and like it has this issue of they fingerprinted the gun but uh they they not the casings that were shot and so like that would be a case where it would be >> interesting. Another one is obviously the recent unfortunate assassination of Charlie Kirk. Like >> yes, >> that would be an example where like this would really go a cuz there's a lot of issue about the weapon and the suspect and all of the kind of the timeline doesn't >> Yeah. quite Yeah. Yeah.

53:47>> So I mean this would be something you know an empirical thing that would be um valuable in that context. >> Yeah. I think I think it's it's a very cool use of just fundamental electrochemistry for a problem that's been around for ages. >> Uh Tory Lanes. I had to say the name cuz I was going to be mad if I couldn't remember it. That was Megan the Stallion and Tory Lanz. [laughter] >> Yeah. Okay. >> I didn't forget, guys. It's a little brain fart. I got it. I got it. I got it. >> I don't know who either. I I'll know who either of [laughter] those people are. >> It's funny because it was a very on Tik Tok. It was a very Anyway, um story