In the early '80s, I caught a local newscast out of New Orleans...and a story similar to what you describe.
They caught this POS that had robbed a string of convenience stores. They knew it was him, as he always used the same MO.
He would choose a store clerked by a female, and pretend to shop until he was the only customer. He would then lay his items, and his package on the counter and demand all the money.
This particular evening he chose a can of peaches. As soon as he whipped it out & layed it on the counter, that girl amputated it with that can.
I'll never forget the policeman being interviewed surrounded by the flashing lights of police cars and an ambulance behind him. His exact words were "he should have bought a loaf of bread".
ROTFLOL!