[voyager4520]

In my state (CO) we have a law that says you can't be subject to civil suits related in any way to a justifiable homicide. We also have a "Make My Day" law (yeah it's really called that) that says you don't have to try to flee from inside your own home when your life is threatened.

Assuming it got to the point of a prosecutor being involved though, the only modifications I'd stay away from are engravings or other emblems like the Punisher Skull that people put on some of their guns. That and anything that violates the laws where I live.