Will the cops take into custody your entire lawfully owned firearm collection, from your locked safe, as well as any other firearms in the house even though they were not used or involved in anyway with your recent defense of your life and home?
That's a good question.
When I took John Farnam's course, he advised us to keep our gun safe locked, and don't answer any questions in regards to it's contents.
Do not have conversations with your neighbors about the contents of your safe, or how many guns you own.
Obviously, don't put the gun you used in the shooting back in the safe before the police arrive.
As we know, there are jurisdictions where they police are quite capable of confiscating all guns as "evidence". John also advises that you read your gun magazines and then throw them away. A living room full of Gun Mag.'s can be used against you and prompt the police to look even further.