Jack Mannion is hired as Washington, D.C.'s new police chief after a succesful run in New York and other areas and is instantly greeted with hostility by the city's top brass, led by chief of patrol Joe Noland, who believes he should have been promoted and does not think Mannion is qualified for the job. Chief Mannion becomes friends with Ella Mae Farmer and gives her a new job in the district.
Chief Mannion releases a mandate that will take all illegal guns off the street. He also discovers a motive of the murder of a young man.
Chief Mannion promises to help clean up one of the most crime-ridden blocks in Washington D.C., and Temple is accused of pushing a suspect into traffic.
The department gets upset when Mannion when he adds a special night shift that puts the senior officers on the street during the peak crime hours in D.C.
Terrorist problems are arising in D.C. when Mannion is aware of biological terrorist threats are starting to be found. He must now put all his force out to find this terrorist. Also, an escapee from a juvenille detention murders a taxi driver and now is hiding in the public schools, which endangers hundreds of innocent lives. Temple Paige goes undercover as a student to help hunt down this convict. This causes problems for Ella as well as she almost loses custody of Ricky, her nephew, until Chief Mannion steps in and talks to the judge.
Jack lands himself in trouble when he tries to get rid of bad cops in the district. However, this act leads to cops calling in sick.
Ella worries about Ricky when he testifies against his father in a murder trial. Meanwhile, Nick uncovers evidence against the mayor.
The city must deal with a criminal who is stalking elderly people, takes their life savings, and then kills them. Meanwhile, the Mayor admits the truth about his past.
Mannion tracks down a drug dealer who is supplying executives.
Jack receives a threat from an ex-cop who he had fired. Meanwhile, Ella tries to deal with a group of Santas fighting for the best places around town.
Temple heads up the investigation into a serial killer who is strangling prostitutes.
Mannion gets involved in a case on a personal level when a woman asks for help in finding her husband.
A vigilante is on the loose when a website shows where sex offenders live and work and now have been murdered. Ella finds out that she lives in the same building as a sex offender.
Mannion tries to reunite a boy living in foster care with his mother. Meanwhile, McGregor tries to stop a stalker from harming a woman before it is too late.
Mannion goes on a mission to better protect cab drivers after a driver shoots a passenger he thought was trying to rob him.
Mannion heads to New York forhis ex-wife's wedding. Meanwhile, Noland is accused of a cover up.
A Vietnamese colonel is suspected of running a sex-slave operation. Meanwhile, Nancy confronts McGregor over their relationship.
Mannion decides to go after street gangs following a drive-by shooting that kills a pedestrian. Meanwhile, Nick is beaten badly.
As Mannion's relationship with his ex-wife heats back up, their son, Jack Jr. arrives in town, causing trouble for Mannion and Sherry.
Detective Travis Haywood is shot during an undercover operation and Mannion must deal with the media who promotes the story as a black cop being shot by a white cop.
Temple goes undercover to find a theft mob and later arrest two brothers who head up the gang. Meanwhile, McGregor comes across a stolen bracelet that was involved in a murder investigation five years ago.
When two ex-cops are shot to death while working security at a bank, Mannion suspects that the Russian mob may be behind the deaths. Mannion contacts Monya, a Russian gangster for tips in the case.
Due to his actions in the double murder investigation, Mannion is suspended, forcing Noland to step in.
An early case of Debreno's goes to trial which causes Mannion to question his motives and to determine if he still has a place on the team. Meanwhile the defense tries to use Debreno's personal and professional life to discredit him, and saying that he set up the defendent to impress Chief Mannion.
It's Ella's funeral, and everyone from the MPD come to pay their respects. Those who speak include Chief Mannion, Phil Brander, Detectives Temple Paige and Kevin Debrino, and Nancy Parras.
Mannion is back! After a long vacation in Arizona he starts to 'campaign' for Chief of Police, although it isn't an elected position. He decides to help a poor neighborhood which might get people to like him again, rather then using an illegal taping card that could get him back into office.
Meanwhile Brander decides to rejoin the force and he helps Nancy to investigate Lester Richard's death. Temple is freed from jail after they find that Maria Rodriguez (Cashmere Brown) was lying, although it doesn't prove that he didn't kill Lester vindictively.
When out of nowhere a portrayal from maria appears on Gwen's window, the whole neighborhood gathers together. A few minutes later it appears the spectators are treated with money falling from the sky.
In The District's Series Finale, ChiefMannion investigates the murder of two young women, one of whom is identified as Debreno's on and off girlfriend, Maria.