Season 0 of Line of Duty premiered on March 17, 2016.

Season 1 of Line of Duty premiered on June 26, 2012.

DS Steve Arnott is transferred to the police anti-corruption unit after the death of a man in a mistaken shooting during a counter-terrorist operation by another cop.

Season 2 of Line of Duty premiered on February 12, 2014.

An ambush of a police convoy results in three police officers dead and a protected witness seriously injured. The sole surviving police officer is Detective Inspector Lindsay Denton. Deputy Chief Constable Mike Dryden takes personal charge, assigning AC-12 to the case. Initially AC-12’s most valuable witness, the suspicion soon arises that Denton could be their prime suspect. In the pursuit of corruption, how far will they go to uncover the truth?

Season 3 of Line of Duty premiered on March 24, 2016.

After a criminal is shot dead during a police raid, the AC-12 team begins examining the conduct of Sergeant Danny Waldron, leader of an elite unit. But Waldron’s loyal team obstructs the investigation, and the truth about the shooting proves more complicated than Arnott and Fleming could ever have imagined.

Season 4 of Line of Duty premiered on March 26, 2017.

The fourth series sees AC-12 facing their most devious opponent yet! Under pressure from her superiors, DCI Roz Huntley charges a young man with a series of murders after months of fruitless investigation, but is he guilty? The Chief Forensic Investigator has doubts and turns to AC-12.

Season 5 of Line of Duty premiered on March 31, 2019.

Series 5 follows the actions of Superintendent Ted Hastings, D.I. Kate Fleming and D.S. Steve Arnott as they investigate an Organised Crime Group with links to missing undercover officer D.S. John Corbett.

Season 6 of Line of Duty premiered on March 21, 2021.

Series 6 sees AC-12 facing their most enigmatic adversary so far: Detective Chief Inspector Joanne Davidson, the senior investigating officer of a high-profile unsolved murder.