If someone drops something in my car, and I unwittingly drive off with it, it is still not mine. But I did not steal it. If the person asks for it back, and I refuse, then I am stealing it.
All the police had to do was knock on his door and ask for it back. If he refused, that's grounds for theft. If he denied knowledge of it (like if it had just fallen off somewhere) that doesn't sound like sufficient grounds for a search warrant, and if the search warrant did turn up evidence of some unrelated crime, that evidence shouldn't be admissible.
I'm no lawyer, but that's what sounds right to me.
(I don't agree that Finders Keepers is a legal basis for ownership, or that leaving your door open means it's ok to steal, or that a bank error in your favor means you get to keep it.)
All the police had to do was knock on his door and ask for it back. If he refused, that's grounds for theft. If he denied knowledge of it (like if it had just fallen off somewhere) that doesn't sound like sufficient grounds for a search warrant, and if the search warrant did turn up evidence of some unrelated crime, that evidence shouldn't be admissible.
I'm no lawyer, but that's what sounds right to me.
(I don't agree that Finders Keepers is a legal basis for ownership, or that leaving your door open means it's ok to steal, or that a bank error in your favor means you get to keep it.)