Armed robbery (via gun or otherwise) and a fairly fixed area of operation (near an appropriate parking lot) probably would not last very long. In some states, merely being in possession of a firearm while committing this sort of crime would up your jail time a bit even without drawing it, and even more so if you actively threatened someone with it.

I realized this while typing, but decided to go with it just because it was in the spirit of mocking the comment I was replying to.

Interesting bit about jail times being increased for possessing a firearm while committing a crime though.

Both FYI and to confirm to myself that I wasn't wishfully make that up, I looked up the policy for my home state: http://www.dc.state.fl.us/oth/10-20-life/