What I’m referring to is the ballistic evidence from the bullet (as seen on CSI type shows) as it passes through the barrel, tie it to the gun’s serial number, and put it in a database for law enforcement to use? The gun barrel’s lans and grooves would be on file before the gun was in circulation, making life easier for the police if they recover a bullet from a crime scene.
If not, why not? (Besides money, of course). I would think that this would be a great way to track down guns used in crimes. If a bullet could be matched to the database provided by the gun manufacturers, then they wouldn’t have to build a database on their own, one gun crime at a time.
Maryland has a law requiring “ballistic fingerprinting” to be done before any new handgun can be sold in that state. I don’t know how many other states require this. It’s not nation-wide yet.
The law has been criticized as costing a lot of money while providing little in return. According to Wikipedia, the law has caught exactly one criminal so far, leading many to say that the program has a cost of about $2.6 Million per conviction.
Not to mention that a guns characteristics change over time. Such a database is a useless, wasteful infringement on our rights. Might as well just start collecting everyone’s DNA to keep on file while you’re at it.
I’m wondering how accurate this ballistic fingerprinting is anyway? Are we talking odds like regular fingerprinting or DNA testing where we can say it is almost foolproof? Or is this more circumstantial evidence added to the pile to make a case. Prosecutor, “Bullet markings are consistent with such and such handgun, suspect owns such and such handgun and ballistics tests of that handgun are consistent with the bullet recovered.”
How exacting is it? Do bullet composition and load make a difference in the “fingerprint”? Can it differentiate between individual weapons of the same model and production lot as they roll off the assembly line? If not I’d wonder if such a database had much value at all.
Barrels can be hot lapped. Fire a few bullets “charged” with abrasive and smooth out some of the roughness.
Some say the gun will now be more accurate. A side effect is that the ballistic fingerprint is now changed.
And don’t forget on many handguns the barrel can be changed in a few minutes time.
The wear on the barrel also plays a factor. That is, straight off the assembly line the grooves in the bullets will be far more pronounced. Now fire several thousand rounds through the gun, clean it a hundred times, and THEN fire a test round. You’d be amazed how different it looks compared to the test signature shot at the factory.
…and some firearms enthusiasts frequently change out/replace barrels with customized versions for better accuracy, etc.
Legislation to try and build massive databases of every individual gun is “common sense” legislation which actually lacks pretty much all common sense. Ballistic patterns change over time, and can be impacted by the ammunition used, the wear on the barrel, etc., etc. This isn’t rocket science; pretty much anyone who understands how firearms work or the mechanics and engineering of weapons knows this.
Apparently the existence of ballistics and the influence of idiotic technologically illiterate TV writers are critical for solving some crimes, however. Police officers and detectives I’ve interviewed have told me that they will very often tell a suspect “we ran ballistics on your gun and it’s a dead-match for the bullet we pulled out of the victim” and the suspect will think they’re suddenly in CSI and start confessing or asking for a deal.
Plus it would be a nice way to pin a murder on someone else. Let’s say I have a 9mm. I could hang out at the range and the next time a guy is firing a 9mm, I could pick up his brass. Then, when I commit my murder, I take an extra two seconds to pick up my brass, throw down his, and BAM, ballistic fingerprints link him to the murder…
If you fire a round from a weapon today, then put it away, tomorrow I can fire another round from that weapon and match them with near perfect accuracy or I can eliminate other weapons of the same model. It’s as good as a fingerprint.
If you use that weapon regularly, and I test it in 5 years time after you have put another 1, 000 rounds through it, I have little chance of getting a useful match. I will be able to eliminate some weapons, but I probably could have done that using a database of when the factory was re-tooled.
And of course, if you take the weapon home and spend 2 minutes with a metal rasp, dremel or wire brush, then I can never possibly match it to bullets found at the scene of any crime. The best I will be able to say is that you were found in possession of a weapon of the a type that might have fired the round.
So basically it allows you to catch really stupid and lazy criminals. The ones you can almost always catch without any keeping files on millions of innocent people.
Firearms purchased new in the US come with a fired cartridge case from that weapon. It’s in a factory sealed envelope and in some states is sent to a central repository for evaluation.
As **Blake **pointed out, those fired cases will not match recently fired cases after some number of rounds have been fired. I suspect, and perhaps Blake can answer, that the ability to make a match could vary with the brand of ammunition as well. I’ve seen photos and discussion indicating that using different brand and type of primers in center fire rounds results in vastly different firing pin markings. And to mention micro stamping, that simply takes a few second with a file to defeat.
Seconds for most automatics; if it’s more or less the usual Browning pattern, the barrel isn’t fixed, so you can replace it really easily when you fieldstrip and clean it.
And… while frames are serial numbered, barrels aren’t.
I had no idea that the markings on the bullet could change so much over time to make this kind of database virtually useless. I have always been skeptical about the bullet matching technology being as accurate as a fingerprint or dna, but I guess years of forensic shows have worn me down to accept it as a legitimate marker for guilt.
My biggest question has always been on a mass produced handgun, how different are those barrels really? Yes, they may have microscopic differences when brand new, but after firing a box or two of bullets, won’t they be close enough to add reasonable doubt as to what gun in a production run shot the bullet?
Consider me educated and ignorance fought on this one. Glad my initial thinking was right, however like I said, I do admit falling for the hype. I’m glad isn’t national legislation, and I retract my comment about this being an easy thing to create.
As others have pointed out, it is probably a lousy database. But the technology would still be useful for matching a bullet from a victim to a weapon found on a suspect or, say, disposed of and later found in a river. I think they also use them to tie together serial murders.
I wonder how many guns used in unsolved shootings are later brought to the range and a bunch more rounds fired through them to the point that the barrel marking changes significantly. If I were the shooter, I’d be trying to make sure that gun never saw the light of day again.
The Association of Firearm and Toolmark Examiners (AFTE) published an article years ago (late 70’s? I didn’t make a copy of it) that checked whether or not you could still match a fired bullet to a firearm after 5,000 rounds went through it. They found that you could, thereby quashing a planned fun research project of mine I had hoped was original. There’s at least one other study out there with the same results, though I believe they went through a lower round count.
Exactly what you needed to do to change the rifling characteristics so you cannot make a match I don’t know.
Folks are right that all you need to do is change the barrel, and you’re set. You can but replacements for a Glock, for example, for about $200.
Dunno how hard it would be to change out the marks left on the ejected cartridge case? The extractor and the firing pin to be sure, but I don’t know what marks the chamber leaves against the base.
I think some are missing one easily missed piece of information here. The bullet is not kept, just the empty shell casing. With the casing, all you can really get is the breechblock impression and extractor/ejector marks. The barrel itself shouldn’t matter, those marks are made by the other parts of the gun. (ETA: remembered the most obvious after reading Patch’s post… the firing pin!) Of course, they can change or be altered too.
I’ve never thought about it before, but why don’t they also keep the actual bullet for the database? Cost?
Everything always boils down to cost, so aside from the logistics (you need space to keep the bullets and casings), you need to have an entry in the database to refer to the physical space of the bullet. That’s a nightmare.
I think it’s worth being clear about the distinction between marks left on the shell casing and marks left on the bullet itself.
Much of the discussion in this thread has focused on the gun’s barrel, suggesting that most people have been talking about ballistic fingerprinting as it pertains to the marks left on the bullet as it travels down the barrel—the “lands and grooves” so beloved by TV crime writers. This type of identification isn’t going to be affected by throwing someone else’s brass around the crime scene.
Most of Maryland is a quick car ride from Virginia, the Disneyland of gun sales and ownership. I personally don’t own a gun (and living in Korea, that’s unlikely to change soon). But having lived for long stretches in DC, Maryland and Virginia, I can tell you second-hand that Maryland gun laws are easily gotten around.
Barrels are not too expensive. Brownell’s, Midwayusa, and a dozen others all sell replacement barrels for many common automatics. Swap the barrel, commit the crime, dispose of the aftermarket barrel. Ballistic fingerprint database defeated.