Chicago PD has had lots of adversaries over the years. It's worth noting that when we wrote our list on the 10 most disliked Chicago Fire characters, Hank Voight (Jason Beghe), the protagonist of PD, was on the list!
It all depends on perspective. Voight has crossed lots lines over the course of his career, oftentimes for the sake of justice, but there are other PD characters who made viewers wince whenever they appeared onscreen. Whether they be corrupt, criminal, or just plain annoying.
Here are the ones that stood out most to us: