In the interesting world of law enforcement, the word "cop" has many meanings.  As a noun, it refers to a police officer.  As a verb, however, it has several meanings.  To "cop" may means to steal or, more generally, to acquire.  To "cop a plea" means to admit guilt, often as part of a plea bargain to a lesser offense than originally charged or in return for a lighter-than-usual sentencing recommendation from the prosecutor.  To "cop out" may mean admitting wrongdoing.  There may be others ... but these are the ones with which I have familiarity, in that prisoners often speak to me in court in their own patois, expecting that I will understand it ... which I try desparately to do.