End of Watch

S3, E15: Don and the FBI re-open a 17-year-old unsolved case when the badge of a missing LAPD officer, who is presumed dead, is found at a construction site. The police investigating the case believe that a former gang member-turned- activist was responsible for the police officer's death because he was seeking revenge for the murder of his brother. However, Charlie analyzes the data on the case and discovers the location of where the victim was killed, leading the FBI to a tangled web of suspects, informants and dirty cops.