Wiktionary
cop a plea
alt. (context slang legal English) To plead guilty to a lesser criminal charge than one had been charged with. vb. (context slang legal English) To plead guilty to a lesser criminal charge than one had been charged with.
Usage examples of "cop a plea".
It was soon agreed that the pirates would not - could not - be allowed to cop a plea on this one.
If you say your father hated you as a kid, you can go out and flash the neighborhood, commit rape, or burn down the Knights of Pythias bingo parlor and still cop a plea.
They'd told her that Nelly was undoubtedly going to cop a plea, so there wouldn't be any trial.