“It’s a fair cop!”

Any bad guy who said this to a cop when he was collared was probably ready to cop a plea.

BTW "collar" seems to be a bit of a misnomer. Few of the bad guys I see on the 6 o'clock news are wearing collars. In fact, most of them are wearing 5 o'clock shadows.

This reminds me of another 'cops and robbers' standard "beat the rap" -- which presumably derives from "rap sheet".

In Houston, the cops used to say: "You can beat the rap, but you can't beat the ride."