For some reason, criminals think there is magic in the phrase: "You gotta tell me if you're a cop." Except there isn't and really, police don't. This lead to Leslie Mayfield's predicament. Mayfield was set up by undercover government agents to rob a fake drug "stash" house. Mayfield tried to invoke the "entrapment" defense, but predictably, the court said no. Mayfield was convicted and sentenced to a "whopping" 322 months in prison (that's almost 27 years).
In this opinion from an en banc rehearing, the Seventh Circuit took a long, concerted look at entrapment, concluding that, because it's a fact-based defense, it should have at least been submitted to the jury for consideration. The opinion attempts to settle some confusion within the circuit about the appropriate standard for entrapment.