If I found a firearm in the bathroom I would secure it, but I would not just take it and keep quiet about it.
Calling the police at min and giving it to them would be the wisest move I think.
One should not even touch the firearm. It could have been used in the commission of a crime and have latent finger prints or DNA on it. Just call the police, tell them about the gun, and do not allow anyone in the bathroom until the police arrive and properly secure the gun as evidence.
“Calling the police at min and giving it to them would be the wisest move I think.”
Cops want us to do that because it never happened.