Staffers at a pawn shop in Fort Lauderdale, Florida, thought a man looked suspicious.
A couple of minutes later, a red dye pack exploded in the man's pants.
Police say the man ran and ditched a wad of stolen cash.
According to investigators, the man matched descriptions of a robber who took a bag of cash from a bank about an hour earlier.
The exploding dye pack also contained Mace, which stung the eyes of people in pawn shop.
Police are still looking for the suspect.