Somethng is bugging me about that show, BTW.
Hank Voight started out on Fire. He was just a regular CPD detective who was harassing Casey for busting Voight's son for drunk driving. Voight actually ended up in prison for what he did.
And yet in P.D., Voight is a Sergeant with command of his own division? How the hell did he get there?
Have no idea. I only watch Chicago Fire. Probably something wildly implausible but technically legal.