Now is a good time to not say shit to anyone about it being stolen. Theives are stupid, and if you think its someone you know, they might just ask you if you've ever found out who stole it, even if you haven't told them. Its an old trick my dad said has worked for him. If its someone you don't know, chances are you won't ever know who did it. BUT if they knew where it was in a shed/garage, I would say it was either someone that knew you, or someone that has a friend that knows you, plus the fact they didn't take anything else. They were after something specific, not just smash and grab type shit.