Line of duty Series 3 Ep6

Fairbank is arrested and interviewed on new information submitted by Nash during an identity parade. During the interview, Hastings receives the list sent by Denton which identifies Fairbank as one of the abusers. Meanwhile, Arnott awakens to find his pocketbook missing and his car stolen. As he reports the car missing, Hastings attends a call to a dockers' yard where the body of Denton has been discovered in Arnott's car. Arnott is arrested on suspicion of murder. During questioning, evidence identifying Arnott as 'The Caddy', such as money from Denton's bribe and the mobile phone he used to contact Bains, are shown to have been found in Arnott's gym bag. Arnott realises the evidence records relating to his signing out a firearm have been doctored to suggest he did not return it. He knows somebody within the department has set him up, but has no way of proving it. Cottan reveals that he has suppressed evidence regarding the envelope left by Waldron.
With authorisation from the East Midlands AC-3 superintendent, Fleming has been carrying out an undercover operation into the officers of AC-12. She highlights inconsistencies within Cottan's line of questioning against Arnott. Having spoken with DS Nicola Rogerson, she identifies Cottan was the one who fed AC-12 the doctored file on Ronan Murphy. Hastings confronts Biggeloe, who confirms it was Cottan who gave her the file. Bindra later reveals to Fleming it was Cottan who told her not to inform Arnott of the forensic findings of the envelope found in Waldron's flat. Fleming uncovers CCTV which confirms Arnott's car was driven on false number plates shortly before the time of the murder.
Cottan denies all knowledge of the doctored file and claims Arnott must have been the one responsible, having previously had a relationship with Rogerson. Hastings pressures Cottan on the suppression of the golf tee from evidence, as well as the fact that no blood was found on the tee despite blood being found on both the envelope and the list. Cottan claims he only removed it to prevent Arnott from becoming aware he was investigating him. Fleming reveals new forensic evidence against Cottan – fibres from the rope found at Kennedy's murder scene, in the boot of his car. Cottan strenuously denies any involvement with Kennedy's murder. Hastings probes him on evidence submitted by Morton, which suggests he pressured Morton into wrongly identifying 'The Caddy', and also used a secret mobile phone. Phone records reveal he previously called Hunter several times in the months leading up to his death. Fleming presses Cottan on the lead he claimed to have on Arnott linking him to Denton's bribe, which Hastings points out could not have been the money in Arnott's gym bag, as Cottan had made that claim the night before the money was discovered following Denton's murder.
Questioned about his whereabouts on the morning of Denton's murder, Cottan states that he was at home, but Fleming calls his bluff by implying that she might have visited the flat then and asks him to reaffirm his testimony. Cottan sends a text: "Urgent exit required", to three recipients, 'Removals', 'Talk', and 'Ride'. An armed officer guarding the interview shoots his colleague dead, then fires shots into the interview room, enabling Cottan to escape, and hands Cottan his pistol. Fleming takes the shot officer's weapon and deals with the other armed officer. She catches up with Cottan and dismisses the suggestion that they might have had a sexual relationship, telling him that all along she has been carrying out surveillance on him.
Cottan is rescued by a getaway car which unsuccessfully attempts to immobilise Fleming, who manages to shoot the driver and brings the car to a standstill. As she goes to confront Cottan, the driver fires three shots aimed at her, but Cottan jumps in front of her, taking the bullets. Cottan records a dying declaration that directly leads to Fairbank being imprisoned for ten years. The epilogue reveals Arnott is exonerated and returns to AC-12, where Hastings and Fleming also remain; Fleming receives an award for her bravery and is promoted to Detective Sergeant; Denton receives posthumous recognition for her contributions by the coroner but is buried in a local authority funeral with no mourners; Morton retires on full pension plus disability benefits (although it's known he's faking his condition).