Police evidence "gun rooms" hold guns involved in crimes, not just guns used in the commission of a crime. If your guns are stolen, and then recovered, they will be in the evidence room, until final disposition of the case. In some cases, this can take (literally), years. Your stag handled single action might be phototgraphed many times over months/years while waiting for final disposition. You might get it back, you might not, depending on the jurisidiction, and the judges.
It might wind up in the evidence room because little Jimmy had a bad day and sent a threatening e-mail to someone. Or because Cousin Freddy was in your garage when he sold dope to an undercover cop. Or many other reasons. A gun's use in the hands of a criminal during the commission of a crime is just one of the ways they get into the evidence locker. But, as you noted, the pictures do suggest that.
perhaps we could do something about good people shooting one another.
No need. Outside of actual accidents (which are rare), good
people don't shoot one another.