Line of Duty is a BBC police series created by Jed Mercurio and produced by World Productions. The first series premiered in 2012 and became BBC Two’s best-performing drama series in ten years with an audience of 4.1 million viewers. The second series broadcast began in February 2014; its widespread public and critical acclaim led to the BBC commissioning a further two series. The third series was broadcast in 2016 and the fourth the following year on BBC One. The fifth series was completed at the end of 2018 and broadcasting began on BBC One in March 2019.
In May 2017, the BBC had commissioned a sixth series. COVID-19 has caused filming to cease.
It is the most popular drama series broadcast on BBC Two in the multi-channel era and is a winner of the Royal Television Society Award and Broadcasting Press Guild Award for Best Drama Series. Line of Duty was included in a list of the Top 50 BBC Two shows of all-time and in a list of the 80 best BBC shows of all time. It ranked eighth in The Independent’s list of the twenty greatest police shows of all time and third in a Radio Times poll of the best British crime dramas of all time.
The show follows DS Steve Arnott, an authorised firearms officer, transferred to Anti-Corruption Unit 12 (AC-12) after refusing to agree to cover-up an unlawful shooting by his own team. At AC-12 Arnott is partnered with DC Kate Fleming, a highly-commended undercover officer with a keen investigative instinct. She is swiftly promoted to DS in series 4 and DI in series 5. They work under the supervision of Superintendent Ted Hastings, who is one of several Senior Investigating Officers, along with DCS Patricia Carmichael of AC-3 and those of AC-9 responsible for uncovering corruption within the police force. Throughout the series, AC-12 investigate seemingly disparate cases involving seemingly-corrupt police officers such as DCI Tony Gates, DI Lindsay Denton, Sergeant Danny Waldron, DCI Roseanne Huntley and undercover officer DS John Corbett. AC-12 realise the pervasive nature of corruption and the police’s deep-rooted links to an organised crime group.
The cast includes:
- Martin Compston as Detective Sergeant Steve Arnott, a detective sergeant assigned to AC-12, the anti-corruption unit within Central Police. Previously, he served as a counter-terrorism officer. He transferred after he refused to collude with his colleagues following the fatal shooting of an innocent man.
- Vicky McClure as Detective Inspector Kate Fleming, an undercover specialist. A consummate professional, Fleming is willing to investigate officers inside and outside AC-12. Initially a detective constable, she is promoted to detective sergeant at the end of the third series and to detective inspector following the fourth. Fleming is married with a son.
- Adrian Dunbar as Superintendent Ted Hastings, the senior investigating officer of AC-12. He recruited Arnott, Fleming and Cottan. Once a member of the Royal Ulster Constabulary, it is revealed that Hastings is a Freemason.
- Craig Parkinson as Detective Inspector Matthew “Dot” Cottan (series 1, 2 & 3), an AC-12 officer, initially introduced as a Sergeant on Tony Gates’ TO-20 team. At the beginning of series 2, he is promoted to detective inspector and transferred to AC-9. He is seconded to AC-12 by Hastings. Cottan is revealed to be “The Caddy”, working as a fixer for the organised crime group. He is killed at the close of the third series having escaped from AC-12 custody.
- Lennie James as Detective Chief Inspector Anthony “Tony” Gates (series 1), the head of the serious crime unit TO-20, Tony Gates is renowned for returning the best crime figures of any unit in Central Police. It is this reputation, however, that leads AC-12 to his team. Suspected of corruption, Gates faces an internal affairs investigation that adds further complications to his troubled home-life.
Although the police refused to co-operate with the programme’s producers, the production team was advised anonymously by serving officers and by retired police officers. Use was made of anonymous police blogs.