Ballistic fingerprints over time

[Rabid Rabbit]

Here is the report from the Calif. DOJ about ballistic finger printing. http://www.nssf.org/PDF/CA_study.pdf
In short it says it is useful to identify if the same gun was used in different crimes, but when the population is expanded to include every gun in the state the chance of a match is pretty dismal because of the similarities of markings from using the same tooling. The DOJ determined the cost would outweigh the benefits.

 

[Odd Job]

@ Wacki

That article and the references therein do not have a bearing on the scientific validity of firearms and toolmarks matches. The issue there is about computerised matches.
Even so, there are two aspects of that: ballistic fingerprinting (in the absence of a crime), and digitally recording and cross-referencing images taken from forensic exhibits AFTER a crime has been committed. I don't have references at hand, but I have certainly read of numerous success stories where evidence from one jurisdiction has been matched with that from another, by means of IBIS. In cases where the perpetrator has been identified in one of the jurisdictions, the match has been a starting point for linking him to the crime in the other jurisdiction too.

 

[Rabid Rabbit]

Odd Job,
I don't think anyone is saying ballistic fingerprinting a gun used in a crime is usless. The examples you provid involves a very small population of firearms ie ones used in a crime where the gun was fired. In that case a matching to other cases or bullets collected at crime scenes is fairly easy. Now throw in the 100s of millions guns that have not been used in crimes. Now you have a problem of narrowing down the possible matches. Read the CA DOJ report.

In the 5 or six years that MD has had the finger printing program not one case has been solved with the information. But there was one case where the information was used to help in a case but the bad guy had already been caught. The gun was never found but the information identified his girlfriend as the buyer. Even our State Police said trash the program and put the money to something useful.

 

[Odd Job]

@ Rabid Rabbit

Odd Job,
I don't think anyone is saying ballistic fingerprinting a gun used in a crime is useless.

Indeed, that is the issue with many of the posters in this thread (either that, or they don't know the difference between pre-sales fingerprinting and toolmarks matching involving forensic exhibits).
I read that article, and I understand the cost to benefit ratio, but I am not advocating or condemning pre-sales fingerprinting. I haven't offered an opinion on it thus far.

 

[Zoogster]

Here is the report from the Calif. DOJ about ballistic finger printing. http://www.nssf.org/PDF/CA_study.pdf
In short it says it is useful to identify if the same gun was used in different crimes, but when the population is expanded to include every gun in the state the chance of a match is pretty dismal because of the similarities of markings from using the same tooling. The DOJ determined the cost would outweigh the benefits.

Exactly what my point has been. That while it is an extra tool, that helps when you have already narrowed down possibilites, it is not effective on a large scale. I don't know why a couple people are so adamant otherwise.

California hates guns, if they felt it was effective they would have implemented it if they could show even remotely it was useful when dealing with millions of guns.
The truth is it is really only good if you think you found a gun used in a specific crime you know about, and then test it to see if it is a match. If it doesn't match it does not even mean it was not the gun. Yet as the study showed so many will be flagged by the database as matches that need to be manualy examined that it renders it ineffective on a large scale. Essentialy it just allows you a fishing expedition to take a closer look at the owners of the flagged guns and determine who is suspicious. If you finaly do pinpoint a gun, a large majority of guns used in crimes are stolen so all that manpower has simply led you to a victim. The criminal that stole the gun from him probably sold it on the black market for money for some sort of drug like most burglaries are commited for. If somehow they finaly do track the gun down and it happens to be a match still, criminals share guns and sell guns as well so the suspicious scumbag you are lead to is still not proof of his involvement in the crime.
So then the investigation would switch to trying to find connections and ties with people who may or may not even be connected. If you somehow do find a connection and it points to some little ghetto full of gangs and crime where guns change hands between addicts and gangsters frequently the person found with the gun simply having a connection to the crime or victim in a small area does not necessarily mean it was him. Of course at that point a prosecutor wouldn't care and would be searching for motive. You might take scum off the streets but it wouldn't necessarily even be the right one.

So even when it does work it doesn't pan out for the most common types of murders. Plus it would be a sad day when polishing or weatherproofing your gun is suspicious because it changed the 'fingerprint' the gun makes on the casing. Perhaps every barrel sold needs fingerprinting? Or maybe every breech and firing pin and ejector and barrel needs to be seperately serial numbered so you can try to track when each was in a certain gun and at which point it was polished, weatherproofed, changed to improve performance etc.

Or maybe, just maybe it is a waste of taxpayer money and an extra infringement on gun owners who would get no knock raids when stolen guns, privately transfered guns, guns similar enough to thiers are traced. Since you have to manualy inspect the firearm that would mean a lot of warrants for all those thousands of computer flagged possibilites for every crime.

LEO will soothe you by saying "Oh don't worry they would probably no knock swat raid the more suspicious on the list first. Your past is squeeky clean right?"

 

[wacki]

@Lonestar

This thread is weirding me out, all this talk about tampering with your gun so to throw off investigators. What was the whole reasoning behind this thread??? Something illegal??? Is this the new High Road???

Read the original post. I'm in a debate with an anti as to whether or not we should spend billions of dollars a year tracking and tagging everyones guns. Forensics after the fact work. There is no doubt about that. But the pre-emptive ballistics database does not seem to be about crime IMO.

 

[SDC]

Read the original post. I'm in a debate with an anti as to whether or not we should spend billions of dollars a year tracking and tagging everyones guns. Forensics after the fact work. There is no doubt about that. But the pre-emptive ballistics database does not seem to be about crime IMO.

Tell them it makes no more sense than requiring that a tread-print of every new tire sold has to be taken at the point of sale (as murders HAVE been solved by comparing tire prints left at a scene to a suspect vehicle). It might make a politician or two feel like they're doing something useful, but in practical terms, it's a lot of expense without much practical use, especially since "crime" guns circulate in a black market that aren't subject to these sorts of controls anyway.