Line of Duty Series 6 Episode 5: Marcus Thurwell, Homozygosity, Lawrence Christopher Questions & Theories

We delve into the burning questions and theories behind this week's insanely entertaining, thought-provoking Line of Duty episode. Spoilers!

Line of Duty 6-5
Photo: World Productions

Warning: contains spoilers for Line of Duty series 6 episode 5

The pause button really came into its own in this week’s Line of Duty instalment, which was even more packed than usual with references to the past. It saw the return of Patrick Fairbank, and the new arrival of a potential ‘H’ candidate played by Jimmy Nesbitt, plus a cliffhanger that threatened the end of DI Kate Fleming (see below for more on that). On top of all that, it turned out that Jo Davidson being related to Tommy Hunter wasn’t the worst of her DNA revelations; her family history is a sad one indeed. After reading our weekly episode review, dig in to the theories and questions below.

What do “runs of homozygosity” mean for Jo Davidson’s DNA?

That she’s a product of incest. The forensic results show that Jo inherited the same DNA sequence for a gene from both her biological father and biological mother, indicating that they were related. We know that Jo is a blood relative of Tommy Hunter, but we don’t know if he’s her brother, father, uncle or cousin. As Jo’s biological parents were related to each other, he could actually be any combination of the above, though as there’s just a 13 year age difference between them, father seems less likely.

We know that Tommy was a paedophile who sexually abused boys at Sands View Children’s Home. Did he also sexually abuse and impregnate a sister, resulting in Jo’s birth? The existence of Tommy’s son Darren Hunter, shows that he did father at least one biological child with a woman. Or could Jo have been the product of incestuous sexual abuse between Tommy’s father and his sister? 

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Who is Marcus Thurwell?

Only mentioned by name back in series three, Thurwell is a retired officer who’s just shot to the top of the list of suspects for “The Fourth Man”, or the bent copper previously known as H. As seen in police record photographs, he’s played by Jimmy Nesbitt, who’ll presumably be making a proper appearance in the final two episodes of series six. (Nesbitt, incidentally, is also the star of Chris Brandon’s Belfast-set crime drama Bloodlands, produced by Line of Duty creator Jed Mercurio.)

Marcus Thurwell was a DCI at South Ferry Station (Danny Waldron’s former place of work) when he took early retirement aged 40 in 2005, having joined Central Police in 1984, aged 19. He’s currently thought to be living/on the run in Spain. In 1998, Thurwell was the senior investigating officer on the case of Oliver Stephens Lloyd, a social worker who was murdered but whose death was recorded as suicide. Stephens Lloyd was pursuing allegations of child sexual abuse by residents at Sands View children’s home at the time of his murder, and was killed for his silence by the OCG, which was running the child sex abuse ring that included politician Dale Roach, senior police officer Patrick Fairbank and OCG leader Tommy Hunter. Thurwell is suspected of having covered up the murder on behalf of the OCG. 

Thurwell, along with current Chief Constable Philip Osborne, and imprisoned former Det Supt Ian Buckells, was part of the team investigating the 2003 death of Christopher Lawrence, a young black architect who died of his injuries after being hit on the head with a lead pipe in a racist attack by a gang of white youths. Taken into custody for erratic behaviour following the attack, Christopher was racially mocked by police officers, not given medical treatment, possibly attacked further by the officers, and died in his cell. One of the white youths identified by anonymous witnesses as having attacked Christopher was Darren Hunter, son of OCG-leader Tommy Hunter. It’s thought that Hunter bribed Thurwell and/or Osborne and/or Buckells to suppress the investigation into his son’s involvement. 

Is Kate dead?

If you’d rather be held in suspense, move along now, but there’s pretty conclusive evidence that we know the answer to this. It’s all down to the series six trailer, which shows that Kate survived the shoot-out with Ryan. Right at the start, there’s a scene of Kate raising a firearm and shouting “Armed police!” immediately followed by a shot of the lorry park in which a body is visible on the ground, in the right position and angle for where Ryan, and not Kate, was standing. Then at 0:40, there’s dialogue between Jo and Kate, wearing the same clothes as they wore in the shoot-out scene, which we haven’t yet seen. And finally, at 0:44, Jo and Kate emerge from a car with their hands up. It looks like Kate made it this time, but who knows what the final two episodes will bring.

Who gave the order to kill Gail Vella and why?

It was either Marcus Thurwell, CC Osborne or Buckells, all of whom stood to benefit from her murder, but signs currently point to Thurwell, who appears to be running the OCG remotely from Spain and is suspect number one for H/The Fourth Man. Vella was investigating the death of Lawrence Christopher in 2003 (see above) and had likely discovered that the corrupt officers who deliberately botched that investigation to protect the son of OCG leader Tommy Hunter, were the same officers who covered up the murder of social worker Oliver Stephens Lloyd in 1998, to cover up the Sands View child sex abuse ring. Vella was on Thurwell and Osborne’s trail, piecing together the long history of involvement between corrupt officers and organised crime, and she was about to expose it all on a podcast. The day before Vella was due to interview Patrick Fairbank, the senior officer in prison for child sex offences at Sands View, she was murdered. 

How did the OCG/The Fourth Man know what Vella was investigating?

Lee Banks, an OCG member arrested by Steve in series five, agreed to be interviewed by Vella in order to find out what she knew. Two weeks before she was murdered, Vella asked Banks questions that revealed she was getting close to uncovering high-ranking corrupt officers. He fed that information back to his active-OCG-member brother Carl Banks, who sent it up the chain and eventually received an order to kill Vella and steal her laptop and phone, to suppress her investigation.

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So Jo is “definately” being blackmailed by H/The Fourth Man?

The rogue misspelling of the word ‘definitely’ says so, yes. In series five, when John Corbett and Lisa McQueen were communicating with ‘H’ via an online chat room, he misspelled the word with an ‘a’. Later that series, Ted Hastings mimicked the misspelling when he was posing as H as part of a plan to expose the OCG. In this episode, when Jo is told by H/The Fourth Man to get rid of Kate Fleming, she asks for confirmation that it will be her final job for him. The reply “Definately,” therefore, it’s the same person John and Lisa were talking to about the Eastfield Depot raid. 

So PCC Rohan Sindwhani was on Ted’s side after all?

Yes. Although his proximity to corrupt senior legal counsel Gill Biggeloe, concern with public perception and general antagonism towards Hastings and AC-12 made him look suspicious, Sindwhani was apparently on Ted’s side all along. When Sindwhani, an elected independent police and crime commissioner, announced in the findings of Operation Pear Tree that there was no institutionalised corruption in Central Police, he looked like part of the conspiracy, but no. This episode we learned that he’d been arguing AC-12’s case behind the scenes. 

Why did Sindwhani resign?

Chief Constable Osborne (who we now know was an investigating officer in the Lawrence Christopher cover-up) turned on him for trying to stand in his way and prevent the closure of AC-12. Osborne made a televised statement against the role of the PCC, criticising political appointments to the police service, and using Brexit-tinged rhetoric to call police and crime commissioners unaccountable bureaucrats, demanding that the police “take back control”. That left Sindwhani in an impossible position: do nothing and look weak, or fire Osborne and lose the support of rank-and-file officers. He chose to resign, but urged Ted Hastings to use his remaining time to uncover the corruption at the heart of the service.

Why did Hastings change his mind over bringing in Ryan Pilkington?

Because he now has to work against the ticking clock of the anti-corruption restructure and his imminent retirement. Before, Ted wanted to bring in Ryan to protect Kate and she refused, preferring to keep watch on him. Now that Ted knows he has a deadline, he’s chosen to take the risk of leaving Ryan on the streets, in the hope that he’ll lead them to the top man. 

In short: no, Ted’s still not bent, though he did make the dreadful mistake of leaking to Lee Banks that there was a rat in the OCG’s unit back in series five, indirectly causing the death of DS John Corbett (hence the 50K guilt money paid out to John’s widow Steph).

Is the Lawrence Christopher case inspired by a real investigation?

It appears to be an amalgam of the 1998 death of Christopher Alder and the 1993 murder of Stephen Lawrence (presumably explaining the name). Christopher Alder died in police custody after suffering a head injury outside a nightclub. Audio recordings showed that police officers refused Alder medical treatment and racially abused and mocked him while he lay dying. None of the officers involved were charged. Stephen Lawrence, who planned to become an architect, was stabbed to death in a racist attack by a gang of white youths while waiting for a bus.

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The fictional Lawrence Christopher case shares similarities with both real-life cases, including the flawed, racist and allegedly corrupt investigation into Stephen Lawrence’s murder. Anonymous witnesses named Lawrence’s killers in the immediate aftermath of the attack, yet only two of the five suspects were charged with the murder in 2012, almost twenty years after their crime. It’s alleged that corrupt officers protected the killers, who included David Norris, the son of drug baron Clifford Norris, who was alleged to have bribed police officers to suppress the investigation, just as the fictional Tommy Hunter bribed officers to protect his own son. 

Line of Duty continues next Sunday the 25th of April at 9pm on BBC One.