If it were a kitchen knife, could they go door to door asking people to have their knives tested for blood? Their hands, while they are at it?
Or maybe, like the Skakel case (I think), if the weapon were a golf club, then you could ask everyone who has a three iron to come on down to the station.
To make people a suspect because they legally own something is a little off. And asking for a ballistic test is making you a suspect.
One thing that's upsetting is the gun registration angle, which most FReepers dislike. If we had centralized registration, this would happen lots more often. They went knocking doors of AR15 owners during the Maryland sniper case until someone videotaped their interaction with the authorities.
If the police showed up at your door asking to see your gun “just for some testing”, would you comply without considering the risk you are taking?
Ballistic “fingerprinting” accuracy is way overblown, they could easily get a hit on your .40. How many times have they tested James Earl Ray's gun, and arrived at different conclusions? Now you are a murder suspect because some tech sees unique identifiers in your gun barrel, or on the ejected rounds, because you volunteered and in so doing waived some rights and guarantees.
I don't believe you. Ballistic testing has been accepted in courts for decades... it isn't subjective like the lie detector...