50 Fun Facts About Line of Duty

Who created and wrote every episode of Line of Duty?

Mercurio also directed some episodes and called the show a "revisionist commentary on 21st-century policing".

What is the name of the anti-corruption unit at the heart of the show?

AC-3 and AC-9 also exist in the show's world; in series 6 Osborne plans to merge all three and cut staff by 90%.

On which channel did Line of Duty first air in 2012?

It became BBC Two's highest-rated series in a decade before being promoted in 2017.

In which year did Line of Duty move from BBC Two to BBC One?

The move followed a restructuring of the two channels and the show's huge BBC Two ratings.

Which character does Martin Compston play?

Compston is Scottish and adopts an English accent for the role; his three-piece suits made the waistcoat a running joke.

Vicky McClure plays which AC-12 officer?

Fleming starts as a DC and is promoted to DS at the end of series 3 and DI by series 5.

Who plays Superintendent Ted Hastings?

Dunbar was only supporting cast in series 1 and was promoted to the main credits from series 2.

Which corrupt DCI does Lennie James play in series 1?

James was offered the part without an audition and flew back from Los Angeles to film it.

Keeley Hawes plays which officer investigated in series 2?

Hawes said that when she first got the script, Mercurio had not yet decided whether her character was actually corrupt.

Which actor plays firearms officer Sergeant Danny Waldron in series 3?

Mays' character is killed early, with the script changed to bring Lindsay Denton back for the rest of the series.

Thandie Newton's series 4 character is which DCI?

Huntley ends up losing a hand to an MRSA infection traced back to forensic coordinator Tim Ifield.

Stephen Graham plays which undercover officer in series 5?

Corbett uses the alias John Clayton; Graham consulted a friend in Army intelligence who had done real undercover work.

Kelly Macdonald's series 6 character is which DCI?

Davidson turns out to be the product of incest in the Hunter family and names Patrick Fairbank as her believed father.

Which company produces Line of Duty for the BBC?

World Productions also made Mercurio's Bodyguard; Simon Heath is its executive producer on the show.

Where was the first series of Line of Duty filmed?

The show's setting was later changed to a vague Midlands on the BBC's advice, and production moved to Belfast.

From series 2 onwards, in which city was Line of Duty filmed?

Belfast Central Library's exterior serves as the police headquarters facade.

What peak audience did the series 6 finale reach in its final 15 minutes?

That made it the highest-rated UK drama since modern records began in 2002.

Who is finally unmasked as "the Fourth Man" in the series 6 finale?

He demands immunity and witness protection, is told he qualifies for neither, and is arrested.

What nickname does the crime group's man inside the police go by in series 1–3?

The name comes from his past carrying golf clubs for gang boss Tommy Hunter.

Which three-word text summons an armed escape during a series 3 AC-12 interview?

The scene was later shortlisted for Virgin TV's Must-See Moment award.

Which AC-12 officer murders Denton in series 3?

Denton refused his bribe and emailed the abusers list to Hastings moments before she was shot.

Which senior officer accuses Hastings of being "H" in series 4?

Hilton is later found dead at the same spot as a murder linked to the Sands View boys' home.

What does Huntley lose to an MRSA infection in series 4?

The infection is traced to Tim Ifield, which helps prove she killed him.

How many years is Huntley sentenced to for Ifield's manslaughter and cover-up?

She admitted killing Ifield in self-defence and framing her husband Nick for it.

What is the codename of the series 5 undercover op that embedded Corbett in the OCG?

Gill Biggeloe helped select Corbett for the operation and steered him towards investigating Hastings.

The series 6 investigation into journalist Gail Vella's murder is known as what?

Vella had been developing a podcast about high-level police corruption when she was killed.

The murder of Gail Vella was based on the 2017 killing of which journalist?

Caruana Galizia was the Maltese investigative journalist killed by a car bomb.

The show's opening scene was credited to the 2005 police shooting of which man?

De Menezes was wrongly believed to be connected to the London bombings.

What is the name of the boys' home at the centre of the series 3 abuse storyline?

The BBC was uneasy about the storyline's references to Jimmy Savile but Mercurio persuaded them to keep it.

Davidson's team in series 6 is based at which police station?

The station set was built inside a former school so the crew could ventilate and distance during the pandemic.

Davidson's DNA is found to be a partial match to which crime boss?

The result indicates incest, and she later names Patrick Fairbank as her believed father.

How much cash is found in Hastings's hotel room in series 5?

Moffatt later claims it was only half the sum; the other £50,000 is never found, and Hastings is seen handing Steph Corbett an envelope.

How old was Gregory Piper when he first played courier Ryan Pilkington in series 1?

Ofcom censured the BBC over its duty of care to Piper; he had to re-audition to return as a police officer in series 5.

Who composed Line of Duty's incidental music and theme?

Her four-note motif was designed so you can hear the words "Line of Duty" in it.

Which comedian played hapless lawyer David Rickman in the 2020 Sport Relief sketch?

Rickman ends up confessing to being "H" after everyone leaves the room — unaware the tape is still running.

What was the show's creator's profession before he became a television writer?

He answered an ad in the British Medical Journal and wrote Cardiac Arrest under the pseudonym John MacUre.

Which other hit BBC thriller did the show's creator make in 2018?

Bodyguard starred Richard Madden and Keeley Hawes, Line of Duty's Lindsay Denton.

Arnott became famous for which item of clothing?

Compston credits the idea to a friend's experience working in a call centre.

Which actor quit series 2 after two days of filming and was replaced by Mark Bonnar?

Bonnar took over the role of Deputy Chief Constable Mike Dryden and earned an award nomination for it.

Which US streaming service premiered series 6 exclusively in the United States and Canada?

Earlier series had bounced between Hulu, Acorn TV and AMC as distributor after distributor collapsed.

What did the series 5 crew have to import from London because local sales are restricted?

"Balaclava Man" is a recurring menace from series 4 onwards.

Which supermarket accidentally sold the series 5 DVD a day before the finale aired?

Acorn Media handled the home releases in both the UK and the US.

Which channel originally turned Line of Duty down as too "problematic" for a mainstream audience?

BBC Two commissioned it nine months later; the show ended up back on BBC One anyway.

Hastings's colloquialisms were partly inspired by Dunbar's father, who was what nationality?

The other source was Mercurio's own Italian father, a former coal miner.

Which unit does Gates lead in series 1?

Tactical Operations Unit 20 includes Dot Cottan and Nigel Morton, played by Neil Morrissey.

Anna Maxwell Martin plays which officer who interrogates Hastings?

DCS Carmichael only appears in the final two episodes of series 5 and returns for series 6.

Under which pseudonym did the creator write his first series, Cardiac Arrest?

He was still a practising hospital physician when he answered an ad in the British Medical Journal.

Of what is Denton convicted at the end of series 2?

She receives a life sentence, while Dryden gets a suspended sentence and resigns.

What punishment does Hastings receive at the end of series 5?

He keeps command of AC-12, though the missing second £50,000 hangs over him into series 6.

How many episodes did the BBC commission for series 7 in November 2025?

Compston, McClure and Dunbar all return, with filming in Belfast from spring 2026.