A reporter accuses Mannion of committing a war crime in Vietnam 22 years ago by ordering 18 innocent people to be killed, and one of the chief's fellow soldiers confirms the story. Also: Temple and Debreno search for a 15-year-old boy they suspect is planning to carry out a murder in order to join a gang.

Mannion's uncle, a retired New York City cop, visits and immediately gets involved in a murder case/jewelry heist; Debreno and Nancy transport a woman who witnessed a fatal shooting to Chicago, where she is scheduled to testify. But, she persuades her escorts to let her first visit her estranged daughter.

After a video where Brander arrests a drug addict is made public and turned into a abuse of power issue, the Mayor demands that Mannion fires Brander, which he refuses to do giving that the man was found innocent. Instantly, a major riot breaks out in the city, with the citizens protesting and attacking the police, demanding that Brander gets fired. Several police cars are bombed and set on fire, and Nancy rescues an officer from an angry riot. He's badly injured, and asks her out when he comes by to pick up his dog. Meanwhile, Temple witnesses his friend Reese die while trying to find the man who shot him. Mannion is trying to save Brander, but when he can no longer live with his guilt he turns in his badge. Unfortunately, the mayor taped Mannion's conversation with Brander over the phone and fired him for obstruction of justice. Late at night, Clive calls him up, saying that Ella died unexpectedly.

Mannion wants to believe that it was self-defense when his attractive fencing teacher's husband is killed at her studio. Meanwhile, Debreno recognizes a suspect in a drug case as his childhood friend who convinced Debreno to go into the Police Academy.