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Fingerprints Recoverable From Cleaned Metal 178

Posted by Soulskill
from the leaving-a-mark dept.
dstates points out a recent article from guardian.co.uk which discusses a new method by which to recover fingerprints from metal. The method relies on corrosion caused by sweat and other biological residues on the metal's surface. Quoting: "The patterns of corrosion remain even after the surface has been cleaned, heated to 600C or even painted over. This means that traces of fingerprints stay on the metal long after the residue from a person's finger has gone. The chemical basis of the change is not yet clear, but [Dr. John Bond] believes it is corrosion by chloride ions from the salt in sweat. These produce lines of corrosion along the ridges of the fingerprint residue. When the metal is heated, for example in a bomb blast or when a gun is fired, the chemical reaction actually speeds up and makes the corrosion more pronounced."
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Fingerprints Recoverable From Cleaned Metal

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  • Plastic weapons (Score:2, Insightful)

    by Anonymous Coward

    This will open up the renaissance of plastic weapons.

    • Re:Plastic weapons (Score:5, Insightful)

      by shadow349 (1034412) on Sunday June 22, 2008 @09:45AM (#23893873)

      This will open up the renaissance of plastic weapons.
      Or, you know, gloves.
    • by Gewalt (1200451)
      Or perhaps it will cause criminals to start taking better care of their guns. A well oiled gun won't have this problem.
      • Re: (Score:3, Insightful)

        by mabhatter654 (561290)

        it would seem to be only circumstantial evidence though.. nearly every person who fired the gun would leave a "permanent" fingerprint. That would reduce the utility of this. I suppose what they're after is damaged metals though. Like from bombs or car crashes during persuit to be able to figure out who the guy working on the metal was when he's cinders.

      • Re: (Score:2, Insightful)

        by nospam007 (722110)

        Or perhaps it will cause criminals to start taking better care of their guns. A well oiled gun won't have this problem.

        Or use stainless steel guns.

        I guess the most impact could be if they could check guns from unsolved crimes from the last 50 years, if no dumbwit copa handled them without gloves that is.

  • Damnit! (Score:3, Funny)

    by jawtheshark (198669) * <slashdot&jawtheshark,com> on Sunday June 22, 2008 @09:27AM (#23893743) Homepage Journal
    Damnit! I knew I should have used plastic vats to hide the bodies!
  • I wonder (Score:5, Interesting)

    by oodaloop (1229816) on Sunday June 22, 2008 @09:27AM (#23893745)
    how many peices of evidence for earlier crimes we can now find a print where we couldn't before? Maybe solve an unsolved crime or two, or free someone innocent? The ramifications for Iraq alone where we can match prints on IED remnants to current detainees is enough to keep me interested.
    • Re:I wonder (Score:5, Insightful)

      by txoof (553270) on Sunday June 22, 2008 @09:36AM (#23893817) Homepage
      That's a really good question; it could be a huge boon for unsolved cases, vindicating wrongfully convicted individuals. I could also be a huge disaster for police departments. Thousands upon thousands of individuals appealing for reexamination of fingerprint evidence could swamp crime labs.

      That being said, it is far worse to convict an innocent individual than to let a guilty man go free.
      • Re: (Score:3, Interesting)

        by Ucklak (755284)

        Except now we're all going to be fingerprinted so they can match these rogue fingerprints.

        • by drinkypoo (153816)
          You mean you haven't been already? My mom had me fingerprinted in school. Thanks, mom. Oh well, at least there's still gloves.
          • Re: (Score:3, Informative)

            by Muad'Dave (255648)
            Question: Did she submit the prints to the police, or did she get the only copy in case you were kidnapped? Around here, the prints _only_ go the the parents to hang onto in case the unthinkable happens.
      • Re:I wonder (Score:5, Insightful)

        by cluckshot (658931) on Sunday June 22, 2008 @10:29AM (#23894193)
        This really drives one to another issue. The longevity of the fingerprints will remove their value. All a finger print proves is proximity. As long as a finger print is there, it proves nothing but attendance. If it was a bio-subtance it had a short life span making it not only presence in definition but also proximity in time. That made finger prints useful. The problem here is that these now become "Undated" finger prints and as such unable to be related to events which was their only value in crime ID other than to have a list of suspects. This points out the most amazing reality about the crime "proof" we see in labs today. For the most part science is destroying evidence entirely. For example: Photos once were valuable. Then retouching started. Then it went to digital where retouching could be infinite. In the end, a photo is little more than fiction in court. Sound prints same. Now we see the ability of the police to fabricate evidence against someone to fullest extent unless we all are aware of what can be done.
        • Re:I wonder (Score:5, Interesting)

          by mikael (484) on Sunday June 22, 2008 @10:49AM (#23894335)

          Just imagine all the suspects involved with fingerprints on the brass cartridges:

          1. The packing person who took the cartridges and placed them in a cardboard box.

          2. The shop owner who took the cartridge out of the box to ensure it was a match with what the customer wanted.

          3. The actual person who loaded the weapon.

          If one fingerprint overwrites another, then it's not a problem. But what if the corrosion effect is additive and you get two patterns merged together. Would forensic experts be able to separate the two or would they get false positives with other fingerprints of innocent people?

          • by camcorder (759720)
            Even though it's wrong target, you can still trace back to see to whom shop owner sold those cartridges. With out those fingerprints it's unlikely that you will be able to identify who sold them. Checking trade records might lead you to the correct target. If you're talking about a murder case or assassination such evidence is invaluable to resolve the case. It may have more value than the actual fingerprint of the shot man.
            • Re:I wonder (Score:5, Informative)

              by NF6X (725054) on Sunday June 22, 2008 @02:55PM (#23896321) Homepage

              Even though it's wrong target, you can still trace back to see to whom shop owner sold those cartridges.

              Cartridges are not serialized. Even lot numbers are just marked on the carton, not on the cartridge, and any given production lot can end up being split between many, many sellers. With a shelf life measured in decades, a box of ammo might sit around on the shelf for a long, long time, and may change hands many, many times before being used. It's not even that unusual to use surplus ammo dating back to WW2 or before. A brass cartridge might have the year of manufacture stamped on the head (more likely for military ammo than for civilian ammo), and there are no markings at all applied to the projectile.

              In general, it would be pretty hard to trace an arbitrary cartridge back to a particular seller or buyer without other evidence. About all that you can determine from a shell casing found at the scene of a crime would be the manufacturer, caliber, possibly the original year of manufacture (and that shell casing might have been reloaded numerous times after that), fingerprints of one or more persons who have handled it, and it may be possible to determine that it was fired in a particular firearm if (and only if) that firearm is recovered, and has not been modified, repaired, serviced, upgraded, or even fired a large number of times since that shell casing was fired in it.

              You probably will not be able to trace a cartridge to a buyer or seller unless the box it came out of is also left at the scene with its credit card receipt taped to it, and even then it could be argued that a receipt indicating that particular brand and type of ammo (if the brand and type is even listed on the receipt) didn't correspond to that specific box of ammunition, and/or that the shell casing did not come from that specific box. It would be much like trying to match an individual paper napkin to a particular package, manufacturer, seller and buyer.

              The FBI used to claim to be able to match a bullet to a specific manufacturing lot based on chemical analysis of the bullet's lead, but that technique has since been shown to be bogus.

              • by mpe (36238)
                In general, it would be pretty hard to trace an arbitrary cartridge back to a particular seller or buyer without other evidence. About all that you can determine from a shell casing found at the scene of a crime would be the manufacturer, caliber, possibly the original year of manufacture (and that shell casing might have been reloaded numerous times after that), fingerprints of one or more persons who have handled it,

                Plenty og scope for fingerprints to get on a cartridge. Especially if you were to have s
                • by NF6X (725054)

                  Recovered soon after a crime. Problem is that it would be difficult to match cartridges which have been used several times, quite possibly in different guns.

                  True. The firing pin's imprint in the primer (which gets replaced with a new primer for each reload) would be valid, but things could be complicated by multiple sets of bolt face imprints on the case head.

          • by txoof (553270)

            Just imagine all the suspects involved with fingerprints on the brass cartridges:

            1. The packing person who took the cartridges and placed them in a cardboard box.

            2. The shop owner who took the cartridge out of the box to ensure it was a match with what the customer wanted.

            3. The actual person who loaded the weapon.

            It's not that big of a deal to eliminate individuals once the prints have been pulled. If a crime is committed in say Idaho, and the shells were manufactured and packaged in Virginia and prints from A (criminal), B (packager), C (store owner) are pulled, it's trivial to eliminate the B set as being irrelevant.

            Under normal circumstances, person B will be flagged as a suspect (because her prints are on the brass) and once it is determined that she was in Virginia when the crime was committed, she will be

            • by beav007 (746004)
              That only works when you know who the owner of the fingerprint is. If persons B and C are not in a fingerprint database, all you have are unmatched fingerprints on the casing, which may or may not be related to the crime.

              That is WORSE than unhelpful, because you then have to try and establish that they are unrelated to the case at hand, without knowing an identity.
        • by DarkOx (621550)

          Well this could be used to exonorate people. I mean you can make a reasonable doubt argument that.

          Hey if I shoot him then you should be able to find a finger print on the gun, given the whitness says I did not ware gloves. Since you can't its resonable the whitness is lying or mistaken as they often are.

          This could be a big help to the falsely accused.

        • Re:I wonder (Score:4, Insightful)

          by Dorceon (928997) on Sunday June 22, 2008 @11:23AM (#23894551)
          Of course the ability to find old fingerprints doesn't mean it's no longer possible to dust for prints the traditional way. You know, the way that does prove proximity in time?
        • The requirements are pretty though though:

          You need a special camera version which contains firmware (hopefully tamperproof) which uses public key crypto to digitally sign each photo as it taken, making it possible to prove that the photo file hasn't been modified at all.

          One example is the Fujifilm IS Pro which can be delivered in this form:

          dpreview Fuji IS Pro review [dpreview.com]

          Terje

          • by TheLink (130905)
            In theory you should be able to get the key from the camera and use it to sign whatever photo you create.

            If the feature actually works (keys/crypto not broken etc), you know that photo or tampered photo is unlikely to be created by someone without access to that key.

            But if you have had access to the camera, you might have the key.
        • by syousef (465911)

          This really drives one to another issue. The longevity of the fingerprints will remove their value. All a finger print proves is proximity. As long as a finger print is there, it proves nothing but attendance.

          Fingerprints are just a tool.

          Traditional fingerprints can be used where time you are trying to determine if someone was there recently. This new technology may be useful in a case where the suspect claims to have no connection with a place or object. They'd need to be used more carefully and their use

      • Re: (Score:3, Insightful)

        by couchslug (175151)

        "That being said, it is far worse to convict an innocent individual than to let a guilty man go free."

        At a one/one ratio, but some friendly casualties are inevitable. We accept a certain baseline of victims and injured/KIA police as the cost of fighting crime. We also tacitly accept a few wrongful convictions...

        • by fluch (126140)

          Would you feel the same if they would put you into jail for many years for something you haven't done?

          • Re: (Score:3, Insightful)

            by couchslug (175151)

            My "feelings" are not relevant to the facts, which I noted above. While it is the duty of law enforcement to try to avoid punishing the wrong people, it is not rational to expect that it will never happen.

            I would be trying everything I could to get any wrongful conviction reversed, but I would still understand that ALL processes have an error rate which, while it can be reduced, cannot always be reduced to zero.

        • Re:I wonder (Score:4, Interesting)

          by muridae (966931) on Sunday June 22, 2008 @11:21AM (#23894541)

          "That being said, it is far worse to convict an innocent individual than to let a guilty man go free."

          At a one/one ratio, but some friendly casualties are inevitable. We accept a certain baseline of victims and injured/KIA police as the cost of fighting crime. We also tacitly accept a few wrongful convictions...

          When does the ratio become acceptable or unacceptable? At 10:1; 1:1; 1:1,000,000 or at either extreme, "Even the innocent should be jailed if it means we catch all the guilty people." or "The guilty should go free rather then an innocent person be jailed."
          • Re:I wonder (Score:5, Informative)

            by cos(0) (455098) <pmw+slashdot@qnan.org> on Sunday June 22, 2008 @01:41PM (#23895641) Homepage

            This question was raised and discussed by Alexander Volokh in n Guilty Men [ucla.edu].

          • by Urkki (668283)

            I think any ratio of falsely convicted innocents is "unacceptable". Unfortunately in reality it is impossible to achieve this ratio. So there's no answer to question of what amount of innocents convicted is acceptable.

            Therefore I think the better question is, when does the ratio of criminals not getting sentenced become unacceptable. IMHO that is an aswerable question, and then the ratio of innocents convicted should just be minimized given the current technology and resources.

        • Re:I wonder (Score:5, Insightful)

          by garett_spencley (193892) on Sunday June 22, 2008 @06:26PM (#23897747) Journal

          "We also tacitly accept a few wrongful convictions..."

          Speak for yourself.

      • Re: (Score:2, Insightful)

        by Digital End (1305341)

        That being said, it is far worse to convict an innocent individual than to let a guilty man go free.


        Tell that to the next rape victom.

        Life isn't black and white, I loath short high and mighty quotes that try to paint it that way.
        • by rthille (8526)

          Or to the innocent man/woman locked up for life for a case of mistaken identity...

          The question is, at what ratio of imprisoned innocents vs freed guilty is suffering minimized?

          • Re:I wonder (Score:4, Insightful)

            by JesseMcDonald (536341) on Sunday June 22, 2008 @05:54PM (#23897583) Homepage

            Perhaps a better question would be: are you willing to take the risk that the person you're locking up may later be proven innocent, knowing that if that happens you'll have to pay restitution for all the pain and suffering you've caused them (not to mention lost wages, etc.)?

            The "correct" balance between false positive vs. false negatives is far too abstract to have any objective answer. This is a situation that calls for a feedback loop, punishment in proportion to the effects of an incorrect judgment. The standard of evidence would then take care of itself. In any event, it is only right that one make up for harm done to others, even when one thought one was doing the right thing at the time.

            • by rthille (8526)

              Sure, but the other side of the coin may be there as well..."are you willing to let this murder/rapist/thief go to commit more crimes, create more victims" if you're wrong the other way...

              Locking someone up who's innocent is bad. So is allowing a murderer to go free to kill again. I'd be nice if we could always do the right thing, but in the absence of that, I say we try for 'least suffering'.

              • Sorry, but I'm not willing to sentence someone before they commit a crime just because I see them as a potential threat. Justice requires that the punishment fit what they actually did to you, not what you or others expect them to do in the future.

                • by rthille (8526)

                  Oh, I'm not advocating locking someone up before, I'm saying that when you have a suspect for a crime, there's a trade off between letting him go if he's the guilty (murderer/rapist/thief) and he kills/rapes/steals again (causing suffering among his victims), and locking him up if he's innocent (and an innocent man/woman suffers). You can guarantee that no innocent person gets locked up, by not locking anyone up, and you can guarantee no guilty person goes free by locking everyone up. The right thing is to

              • by mpe (36238)
                Sure, but the other side of the coin may be there as well..."are you willing to let this murder/rapist/thief go to commit more crimes, create more victims" if you're wrong the other way...

                In many cases it is the same coin. In that you are imprisoning an innocent person whilst letting a guilty person go free. The only exception would be where no crime actually happened. Which appears most likely with rape...
            • by mpe (36238)
              Perhaps a better question would be: are you willing to take the risk that the person you're locking up may later be proven innocent, knowing that if that happens you'll have to pay restitution for all the pain and suffering you've caused them (not to mention lost wages, etc.)?

              With such restitution possibly not fully making up for their loss. Especially in the UK where they are likely to have "board and lodging" deducted.

              The "correct" balance between false positive vs. false negatives is far too abstrac
          • by Fred_A (10934)

            Or to the innocent man/woman locked up for life for a case of mistaken identity...
            At least when someone has been locked up for life and you realise you've made a mistake, you can let him out and more or less try to make up for it (more or less since I guess you can't really).

            When you've killed him, it's too late to do anything. IMO it's the single best argument against death penalty in a judicial system.

        • by Kattspya (994189)
          I will. The alternative is the possibility of being convicted on someones unsubstantiated word.

          Another fairly absurd alternative is filming each and every time you fuck someone or make them sign a contract beforehand.
        • Re:I wonder (Score:5, Insightful)

          by Headw1nd (829599) on Sunday June 22, 2008 @11:42PM (#23899741)
          I'll bite, because we don't need lofty quotes to prove it's worse to convict an innocent man than let a guilty man go free, I can do it with simple algebra.

          Let's take the harm suffered by letting a guilty party go free. We can call it G. We will assume this is a positive value, since I think we can agree that letting guilty people go free is harmful to society.

          Now, let's take the harm of imprisoning an innocent man, which we will call I. Also positive, since putting an otherwise useful member of society in jail for no reason is something I think we'll agree is harmful.

          So let's look at the harm caused by each of our actions. Letting a guilty man free is of course G, as by our previous definition. Now to calculate the value of imprisoning an innocent man, we take our value I, and add G. Why? Well, in convicting the wrong man, we have inherently allowed the guilty party to go unpunished. So we can conclude that that G is less than I + G, i.e. it is better let a guilty man go free than to punish an innocent man.

          Didn't think of that, did you?

          So while convicting an innocent man might give you the opportunity to go tell that rape victim, "It's ok, we got him" it's a lie, and that lie not only destroys an innocent mans life, it lets the real rapist go free.

          • by mpe (36238)
            Now, let's take the harm of imprisoning an innocent man, which we will call I. Also positive, since putting an otherwise useful member of society in jail for no reason is something I think we'll agree is harmful.

            If there was a real crime commited then jailing an innocent person means that someone who is guilty has gone free. The harm starts as soon as an innocent person is charged and any police investigation either stops completely or becomes entirely focused on finding evidence against that person. Even
          • by phr1 (211689)
            Your post raises the question of what happens if someone thinks I is negative.

            Just because someone isn't breaking laws doesn't mean you necessarily think their presence in society is useful. In that case the obvious desired outcome is to round up the guilty and innocent alike from the "useless" part of the population, which means anyone from the wrong ethnic or religious group, political dissenters, people who voted for the wrong party, computer geeks who ask too many questions, etc. So, I think trying

      • by RockDoctor (15477)

        That's a really good question; it could be a huge boon for unsolved cases, vindicating wrongfully convicted individuals.

        You have someone who's been convicted of something ; you institute a second (third, or whatever) re-examination of the forensic evidence gathered at the scene using this technique (it's probably far too late to get new evidence now) ; you find no fingerprints assignable to the convicted person, and petition for a release.
        The first appeal judge say to you "Absence of evidence is not evidenc

      • It could also be a huge disaster for police departments. Thousands upon thousands of individuals appealing for reexamination of fingerprint evidence could swamp crime labs.

        Yeah, that won't be much of a problem... they'll just ignore it. Just like they've done in the past when it's been made obvious that the state has accepted evidence presented by "experts" that actually know nothing.
        This [findarticles.com] article talks a bit about what a problem it is. I don't see the specific case in it that I was looking for though - I know there was a forensic "expert" at hair and fingerprint analysis that convicted hundreds and hundreds of people and the state refused to systematically reexamine or rev

    • Re:I wonder (Score:5, Insightful)

      by Vellmont (569020) on Sunday June 22, 2008 @10:23AM (#23894159)


      how many peices of evidence for earlier crimes we can now find a print where we couldn't before?

      How many pieces of evidence are now ruined, because there wasn't a careful procedure followed in the chain of evidence where nobody touched it? A bullet casing or bomb fragment being criss-crossed with fingerprints isn't exactly going to make this technique any easier.

      • by Kingrames (858416)

        That's not going to slow anyone down.

        it will be easy to run an algorithm that separates one fingerprint from another - ESPECIALLY if they're blatantly differing fingerprints and one of them exists multiple times on the same object.

        This would be like trying to read the stamp on an envelope after the post office has notorized it.
        hardly cause for alarm.

    • by mrmeval (662166)

      I'm surprised this hasn't been done before. Anyone who has handled a carbon steel framed firearm that's blued or parkerized but not painted or otherwise coated can tell you they etch pretty damn well from sweaty fingerprints. I've also seen brass shell casings with fingerprints, the prints turn black with age. There are now lacquer or polymer coated steel shell casings that would limit this effect. They're made of those materials because of cost. Many modern firearms are now coated rather than blued or park

  • by good soldier svejk (571730) on Sunday June 22, 2008 @09:28AM (#23893751)
    At least as it is currently practiced. [wikipedia.org]
    • Re: (Score:2, Insightful)

      by Kneo24 (688412)
      From what I gather there, it's not the methodology that's at fault, it's human error. Perhaps they need better training? In the end I wouldn't say that what we currently have is useless, but only that we should trust those examining the fingerprints a little less, perhaps.
      • Quite right, but a sensationalistic subject line such as 'Too Bad Fingerprinting is Useless' tends to attract karma.

    • Re: (Score:3, Informative)

      by mikael (484)

      You could have come up with a better webpage than that. The Shirley Mckie [slashdot.org] case is a good place to start. The original event happened in January 14th, 1997. A decade later, a public enquiry is only just about to start in September 2008. There is a Wikipedia entry [wikipedia.org]

    • by pnewhook (788591)
      Is that James Baldwin the writer? Regardless, that quote makes no sense.
  • I'll stick to the wood bat as weapon of choice for murder, it can easily be disposed of with fire.

  • by theshowmecanuck (703852) on Sunday June 22, 2008 @09:33AM (#23893799) Journal
    How long do the fingerprints have to be on the metal to corrode it enough to get a good fingerprint from this method? For example, if the perpetrator uses a cloth to wipe the fingerprints off the metal immediately after the crime, will the metal have corroded enough to still give a fingerprint by this method? Or do the fingerprints need to be there for some time in order to corrode the metal enough to give a good print? And if they wipe the fingerprints off is there still enough residue to still corrode the metal, or will they need to wipe the fingerprints off using some sort of solvent or cleaner? etc. etc. etc. It would be interesting to here more.
    • by Kupfernigk (1190345) on Sunday June 22, 2008 @11:12AM (#23894471)
      I have actually done research into chloride corrosion of brasses, and the answer is that it is enormously variable. Whether the brass is turned or stamped, the temperature, the number of steps in the stamping process, the sharpness of turning tools, the final treatment (grind to size, polish etc.) all affect the rate of attack. One would expect much the same for other metals, though considerable research would be needed. This will probably become a nice little earner for expert witnesses.
    • by Feanturi (99866)

      Or what if you "clean" the gun with something corrosive?

    • if the perpetrator uses a cloth to wipe the fingerprints off the metal immediately after
      I'm wondering: If you wipe the metal with your hands before doing it with the cloth, would you redistribute the secretions enough to blur out any information?
  • Passvation layers? (Score:2, Insightful)

    by gboss (968444)
    What about metals with passivation layers, such as aluminum, titanium, and stainless steel? TFA does not address this at all... Sure, brass may be the main metal that they are going to need for shell casings, but a lot of guns are made with stainless steel.
    • And of those guns that aren't made with stainless, they're usually blued, Parkerized, Tennifered, etc. so your question is more than just a minor nit-pick. The finish on practically every gun made is designed specifically to resist corrosion.
  • I wonder how sweaty one should be, for how long the finger should be on the surface of a bullet for it to leave such a corrosive mark, and also whether this applies to other metals, such as stainless steel?

    In any case, wear gloves even while putting bullets into your guns ;)

    • by nurb432 (527695)

      Blah, lost post the first time i tried this.. anyone else have problems with safari blowing up on trying to post?

      Be sure to wear you gloves when building bombs too, and use a "clean box" so you don't leave any DNA behind.

      As far as bullets, if you only touch the cartridge, you wouldn't be leaving any prints on the bullet.. You are taking your cartridges with you and not leaving them at the crime scene, right?

      • And even if you do leave prints on the bullet, they're not going to be too useful once the bullet expands, even if you're using fully-jacketed rounds for some ridiculous reason.
  • by Hognoxious (631665) on Sunday June 22, 2008 @09:59AM (#23893977) Homepage Journal
    If the fingerprints are that persistent, then lots of other marks are going to be there too - probably including lots of other fingerprints. The hard part's not going to be detecting the prints, but separating the relevant ones out from the rest of the item's history.
  • by xdancergirlx (872890) on Sunday June 22, 2008 @10:03AM (#23894017)

    Does this mean that we can see the fingerprints of people that handled old metal objects/chalices/swords/etc.? Maybe it would just be an item of curiousity to have a copy of Julius Ceasar's or Queen Elizabeth's fingerprints but I would put it on my wall! Maybe we could learn something about how fingerprints have changed (or not) over the course of history.

    • by nurb432 (527695)

      In theory, ya.

      • Less likely with swords though. No good swordsman ever touches their blade, only the handle, and that is wrapped, most often in leather. This is because fingerprints will corrode the metal. Swords aren't made of stainless steel, they rust quite easily. Normal sword care involves re-polishing the blade regularly, which should remove fingerprint corrosion if present. Chalices are another story, of course.
  • corrosion? how much? (Score:3, Interesting)

    by Luke_22 (1296823) on Sunday June 22, 2008 @10:41AM (#23894279)
    Great method, ok, but i dubt it works for everyone.

    ok, we all have some corrosive sweat or alike in our skin, but that doesn't mean we all drop out the same amount of corrosive liquid.

    there are people who can not touch a motherboard 'cause it would end with a big mark on the metal, it could even lead to malfunction, this is well known in the industry... I guess they borrowed their idea from here...

    but how much of this corrosive is required for this method to work?
    also, saying "metal" is saying all and nothing... there are metals that corrode easily, others that don't...
    • Re: (Score:3, Interesting)

      by TheRaven64 (641858)
      I don't know the details of this particular technique, but I recently came across an approach to getting fingerprints from fired bullet casings developed by some guys at Swansea which relied on Van der Waals forces - the amount of contact required is very small.
  • I swear I read the same thing in "The Hardy Boy Detective Handbook" as a kid.
  • by Hao Wu (652581)
    Now we can prove whether Oswald killed JFK.
    • Now we can prove whether Oswald killed JFK.
      IIRC, the bullets were lost.
      As was the presidents' brain.

      And anyway, the files are covered up by the government for [life expectancy at the time] after the events, 2033 I think. So "now"... not so much.

  • SANDPAPER!

    fail!

  • I'm pretty sure this is not new, or at least the basic idea isn't. In fact, I recall reading a detective story set near the start of the fingerprinting era, where an old murder case (from before fingerprints were used) was solved by the detective using a fingerprint that was actually visible in corrosion on the doorknob of the room the murder took place in, the room having been closed off since the murder.
  • Pick up your brass.
  • As everyone should know by now, real life is not like CSI. Forensic science isn't the science of discovering who committed crimes, it's the science of making up the most believable science fiction to convince people not to commit crimes, and making up the most plausible BS to bamboozle juries in court. Claims by forensic scientists are generally judged by highly idealised lab situations that bear little relation to real crime scenes. And the scary thing is that when papers are published judging the efficacy
    • Re: (Score:3, Insightful)

      by lpangelrob (714473)

      As my lawyer friend says... the court of law doesn't necessarily judge based on who actually did the crime. It judges on who has the better story.

      That said, the story still has to be based on a fact.

  • money...pennies ?

    Sorry, pun intended ;=)
  • "As you are pushing the magazine in you are actually putting a thumb print on the bullet," said Bond. "That's the person you want. That's the guy who loaded the gun."


    Wow! Just loading a firearm is prima facie evidence of murder!

    So if someone steals my loaded pistol, or even a pistol and ammo I've handled, I'm guilty of murder. Nice.

Heuristics are bug ridden by definition. If they didn't have bugs, then they'd be algorithms.

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