Detective Constable Andrew Flanagan was the detective who oversaw the murder investigation into Alex Moss's murder.
DC Flanagan and colleuge DS Shields turned up at Home Farm to question Declan Macey after his estranged wife Katie Addyman's anonymous tip off that there was a body buried at Home Fields Glamping Site. A few days one of the glamping site's workman Thomas Hillam, tells the police that Declan had paid the workmen to cover the body up. Hillam shows the police where to dig and they uncover human remains. He and DS Sheilds initially suspect Declan and arrest him for perverting the course of justice. They question him over Katie's sudden disappearance and then accuse him of being the murderer, which he strongly denies and is released without charge. The body is later identified as Alex Moss. After punching Declan, Adam Barton is arrested to assault. Whilst being questioned over the assault, DC Flanagan and DS Shields take over the interview and ask him about Alex's murder, suggesting that Alex's relationship with Adam's mother Moira could be his motive. The police find a glove, which Cameron Murray planted, with Adam's DNA in the woods near where Alex's body was buried. Adam claims he is being set up, after being released he realises that one of his gloves are missing from his quad bike. He is convinced that Declan is setting him up and he will go down for Alex's murder so whilst the police are searching Butler's Farm, Moira's boyfriend Cain Dingle punches a police officer and creates a scene so that Adam can escape. Adam escaping makes the police suspect even more that he is guilty.
Only a few days after Adam goes on the run, Debbie Dingle and her aunt Chas go to the police to tell them they suspect that Cameron is responsible for Chas' sister Gennie's murder, and he could also have been the one who killed Alex as well. Flanagan and Shields question them but don't have enough evidence to arrest Cameron. They suggest to Debbie that they put hidden camera's in Debbie's house to get a confession. Debbie initially refuses but Chas manages to persuade her. Debbie agrees to the cameras. After Cameron references that he killed Carl King in The Woolpack and out of reach of the cameras, Debbie insists that she wear a wire to get his confession again. Flanagan and Shield are against the idea but they allow Debbie to wear the wire. Debbie manages to get Cameron to open up but the police do not arrest him so Debbie utters the safe word. Debbie tells Cameron about the wire and cameras. Cameron locks all the doors and holds Debbie hostage, Cameron tells the police that he will kill Debbie if they get any closer. Debbie manages to escape and Cameron is arrested.
In October 2013 DC Flanagan visits Debbie to inform her that Cameron has managed to escape from a prison van. He assigns her security. Cameron puts the police off his scent after he buys a ticket for ferry. He heads towards village and steals a gun and cartridges from the Dingle's van. Cameron takes the Woolpack hostage with many of the villagers inside including Debbie and Chas. Cameron allows all the villagers to leave apart from Debbie and Chas. Debbie and Chas manage to escape but Cameron electocutes himself and dies.
Six months later, after hearing about Clare's Law, Debbie phone Flanagan to ask him to check out her boyfriend Pete Barton, to make sure he is not like Cameron. In September 2014, Declan's sister Megan Macey punches DC Flanagan whilst she is being question for poisoning Declan's step-son Noah Macey.