Someone else pointed out that this would be expensive. Let me try to put in perspective just how expensive.5. I would support a requirement that all firearms sold in the US have ballistics and case-marking information submitted to law enforcement. This should be the reponsibility of manufacturers and importers.
First, you need to understand that criminals could deliberately and easily alter the gun's fingerprint. Every honest gun owner has also altered the fingerprint of every gun he or she has ever fired.
Let me explain how that works.
The idea behind "ballistic fingerprinting" is this: a fired case has unique marks from the extractor, ejector, and breechface. A bullet fired through a barrel also has unique rifling marks. If you store the information in a central database, you theoretically could link a firearm back to the owner. (I say "theoretically" because, to date, none of the ballistic databases has been instrumental in solving any actual crime.)
A ballistic fingerprint is only a one-time snapshot of a gun. Ejectors, extractors, and barrels all suffer wear through normal use, and all can (and should) be replaced at regular intervals. Change one part, and the fingerprint is useless.
But even absent this normal swapping of worn-out parts, every time a gun is fired, the fingerprint changes just a little bit. New scratches appear; old ones are worn away. As time goes on, the fingerprint is completely altered and the data in the files becomes useless. That is why I say that every honest gun owner has altered the fingerprint of every gun he or she has ever fired, and that no law can be passed to prevent it from happening.
Fact is, trying to track a single gun by this method is not like tracking people by their fingerprints. It's more like to trying to ID someone by their hairstyle. It'll work for awhile, but the person can either deliberately disguise themselves by dyeing or cutting their hair, or the normal passage of time will lengthen their hair, turn it grey, or cause it to fall out entirely. Either which way, a hairstyle cannot be considered a reliable method of identifying an individual, because it changes over time. And for the same reason, a ballistic fingerprint is not a reliable method of identifying a gun.
But even if the ballistic fingerprint were akin to a fingerprint and not a hairstyle, it is still a relatively useless tool. Consider the large number of factors which all must be present for ballistic fingerprinting to be useful. If any one is missing, it won't be useful.
1) You must recover a bullet and/or shell casing.
2) The bullet/casing must be in a condition to read. Bullets can be severely deformed, or fragmented into several pieces.
3) The print must not have been altered (purposely or through wear).
4) The gun must be in the system. If there is a government database, there will also be a black market of non-system guns.
4b) The gun must be owned legally. This knocks out a huge swath of crime guns -- in New York, D.C., Chicago, and other big gun-control areas, almost all guns will be outside the system. (Stop to appreciate the irony of that little tidbit; the highest-crime areas are the areas with the strictest gun laws already on the books, and would be least affected by any new laws.)
5) The gun still must be owned by the person who registered the fingerprint, and that person must be the perpetrator or tied to the perp.
6) The gun must be recovered in the possession of the perpetrating owner. "Gee officer, that gun was stolen six months ago" -- indeed, a savvy criminal will make such a report ahead of time to cover his tracks.
In order for ballistic fingerprinting to be instrumental in solving the crime, there must have been no witnesses who can identify the perpetrator. If there were such witnesses, then the fingerprint is really moot.
Of the unwitnessed crimes, there must be no other readily available ways to tie the perpetrator to the crime.
All of the above allows us to analyze the benefit we would receive from the anticipated cost of a nationwide ballistic fingerprint database. The benefit would be limited to a very narrow subset of all crimes: murders that involve guns, from which either an intact bullet or shell casing is recovered, and which crimes cannot be solved in any other fashion. Even when all elements are in place for a good match, the odds are very great that the gun has been fired enough to render those elements useless, and even greater odds are that a criminal will have deliberately altered the gun prior to using it for crime.
So finally we get to the issue of actual cost.
For comparison, consider the FBI's computerized (real) fingerprint database -- Integrated Automated Fingerprint Identification System (IAFIS). It cost $640 million to just implement about 34-35 million records.
Thats about $19 per print just to set up the system. Just getting the estimated 200 million guns into the system would cost $3.8 billion (some estimates go up to 250 million guns = $4.75 billion).
Now let's talk maintenance costs.
While I can't find what FBI spends a year to maintain IAFIS, the system is significantly cheaper to maintain than a ballistic fingerprint system would be for two reasons:
1) Real fingerprints do not change form over time. There would have to be a system to update the ballistic fingerprints every so often, or the records will become useless (see number 3 above). That updating is unneeded with IAFIS.
2) Real fingerprints do not change owners. There would have to be a system to change the ownership records. (Yes, this would be de-facto national registration of gun owners, something that has been vociferously debated and has been ground to a halt every time gun owners have gotten wind of the possibility.)
Incidentally, the system would have to be run by the federal government. The reason we got IAFIS was that the state-level and regional fingerprint systems did not speak to each other.
Bottom line is, I am not convinced that the very limited usefulness of a federal ballistic fingerprinting database would be worth the 4 billion dollar price tag. Nor do I think that its limited usefulness justifies the intrusion into the lives of honest citizens that its implementation would require.
pax