Dealing with criminals

A local policeman had just finished his shift one cold November evening and was at home with his wife.

"You just won't believe what happened this evening , in all my years on the force I've never seen anything like it."

"Oh yes dear, what happened ?"

"I came across two guys down by the canal, one of them was drinking battery acid and the other was eating fireworks."

"Drinking battery acid and eating fireworks!! What did you do with them ?"

"Oh that was easy, I charged one and let the other off."