THE STAR of ITV’s primetime drama following the murder case that shocked Swindon talked about playing the Wiltshire Police detective who got the killer of two women to confess.

Martin Freeman plays Steve Fulcher in A Confession and explained that it was easy to sympathise with the former detective superintendent who resigned from the force after breaching police code of conduct in a desperate bid to find missing 22-year-old Sian O'Callahan.

Mr Fulcher quizzed suspect Christopher Halliwell in a remote location near Barbury Castle for four hours back in March 2011 instead of reading him his rights and taking him into custody.

The taxi driver confessed to killing Sian and unexpectedly admitted to the murder of 20-year-old Becky Godden-Edwards, who went missing in 2003.

He then led the police to where he buried their bodies.

As the drama nears its halfway point, Mr Freeman discussed how he performed the role.

Speaking to ITV News, he said: “You get interested in whatever character it is, whether fictional or real, you start trying to unwittingly bend yourself to that character’s way of thinking.

“It wasn’t hard with Steve Fulcher, I didn’t have to do moral gymnastics to feel that he had my sympathy.

“He absolutely had my sympathy, he paid a very very high price for trying to do the right thing.

“Fulcher could drive you mad, actually, probably because I don’t think he would ever go ‘yeah that’ll be fine, that’ll do’.

“He struck me as someone who was like ‘you’re going to do this and this is going to be done the right way’. Ironically, given that his decisions in the end… breached PACE.”

Mr Fulcher later resigned from the his role as detective superintendent after Halliwell’s confession could not be used as evidence in court because of the Police and Criminal Evidence Act breach.

Halliwell is currently serving a life sentence for the murders he committed.

A Confession creator and writer Jeff Pope consulted the families of the victims, who have praised Mr Fulcher’s actions, during the making of the drama which he considers to be about a moral conundrum.

He explained the thinking process that led to Mr Fulcher's life-changing decision.

Mr Pope said: “As the Police and Criminal Evidence Act dictates, the minute [Halliwell] is arrested and given his rights, he’s brought back to a police station where he will inevitably say ‘no comment’.

“At that point, any chance of recovering Sian alive goes, so [Fulcher] decided ‘I think Sian’s right to life trumps Halliwell’s rights as a suspect’. That was Steve Fulcher’s ethos.”