Chicago P.D. Season 4 (2014)

In District 21, there are two very different groups of police officers trying to keep the streets safe. There are the beat cops who patrol in uniform, and then, there?s the Intelligence Unit, led by Hank Voight. Voight handpicks the best of the best to be a part of his team. The take on undercover work and go after the big fish in homicide cases, organized crime, and trafficking cases. Though the unit is close knit, there?s always the lingering danger of corruption and crossing the line.