There are a couple of local shops that have the doors that open inward, so that you have to pull the thing (and its a heavy pull) to get out. Another shop uses the "airlock" principle, and a third allows you in without problem, but has to buzz you out. The place I like is at the back of a pawn shop, so anybody doing a snatch-and-run has to get past the jewelry case (natural choke point) before the front door is remotely closed and locked. Some have tried, none have succeeded to date.
Used to have a shop just down the street from me, local PD liked to stop by and check things out, until one fellow tried to rob the place (after trying to kick the owners dog, not a smart move). Needless to say, crossfire was the operative term (and the dog was ready to take a rather vital portion of the fellows anatomy as a souvenier). And the fellow walked by the officer's cruiser to boot.