I have a door that's readily opened with a key. However, if you leave the house it locks automatically. Who knows if the Sheriff took the key with him. When we got in there was a key on a ledge. Frankly, we had no idea how the door got locked, but we busted it off with a hammer, and got inside in under a minute. I have this thing about locks and if I'd thought about it a bit I could have gotten inside in 5 seconds ~ BIGGER HAMMER!
You have to have a tungston or titanium bellhousing on the lock to keep out the pros.