Legal issue with letting son keep firearms in his room?

[MED]

Starting in 8th grade, my son kept his long guns in his room (including his pre13 mags). However, I got him a locking steel gun cabinet for them so they were put away. He did have the key, but I trusted him to never pull them out unless he got my permission first. He's 18 now, and I never had an issue. Having them locked up was to address the issue brought up by other posters; I trusted him but not his friends. I personally wouldn't give a minor permission to use firearms on my property without me present because of the liability involved. However, a lot of the air rifles now perform like a 22lr, which would be a lot less risky.