A WORD OF CAUTION
if you intend to mug somebody, don't give them access to weapons to fight back!
In Missouri, two purse snatchers took on more than they bargained for when they tried to snatch the purses of two women shoppers. The women were unloading their groceries when the two would be thieves attempted to snatch their purses from the cart. These women, however, weren't the pushover their assailants believed them to be! One of the women grabbed a shovel from the suspects' pickup and smacked one of the men upside the head. The other woman jumped into the cab and attacked the other suspect, then grabbed the keys so he couldn't drive away.
The guy with the head wound needed to have it stapled shut and both of them were jailed, charged with robbery.
The phrase 'hoisted by their own petard' springs to mind!