AS police drama The Responder returns for a second series, the show's star Martin Freeman has been talking about Liverpudlian accents, getting back into uniform and moral conflict.

The first series of the BBC’s gritty police drama The Responder - which was part-filmed in St Helens - offered viewers a frank and honest insight into the emotional extremes of life on the front line of British law enforcement.

READ MORE: BBC'S The Responder - full cast and when is it on

Written by ex-police officer Tony Schumacher, who spent time working as a response officer in St Helens, it stars Sherlock’s Martin Freeman, 52, as Chris Carson, a crisis-stricken and morally compromised urgent response officer on the beat in Liverpool, who is trying to keep his head above water alongside his partner Rachel, played by Adelayo Adedayo.

The first series ended with Chris heavily traumatised, dishevelled, confused and shocked by things that he has done and lies he has told, and by the the death of his best friend, Carl.

Now the show is back for a second series, set six months on from the events of series one, as Chris tries to repair his relationships and rebuild his life and avoid the corruption that nearly sucked him in last time and Rachel starts to realise she’s got more in common with Chris than she’d ever want to admit.

As star Freeman reprises his role, he explains how Chris’s journey continues.

HOW WAS IT COMING BACK TO PLAY CHRIS? AND WHAT IS IT THAT GETS YOU BACK INTO CHARACTER?

It’s the accent and the uniform – I move differently and speak differently. Any accent you do, it’s a physical act and creates a chain reaction from what you’re creating vocally to the rest of you and the uniform is a big help, it changes how I move and walk because it is so cumbersome and it’s not comfortable.

WERE YOU PLEASED AT THE REACTION TO YOUR SCOUSE ACCENT?

It was a massive relief! It still gives me real joy when I hear people say, “I didn’t know Martin was a Scouser”, and when Scouse people say to me “I didn’t know you were from here”, that’s the best. It’s like being a double agent, I got away with it!

WHAT DO YOU LIKE ABOUT CHRIS AS A CHARACTER TO PLAY?

The reason I wanted to play Chris is that he is a great mixture of vulnerability and strength. I think there is something about a man of few words that is attractive. There’s a reason why people like characters that don’t have to over-explain themselves and I think Chris is one of them. What I like about this show is that we weren’t judging him. You don’t always like a person but that doesn’t mean you write them off as a human being completely. Chris doesn’t always have to be doing the right thing and that appealed to me. He’s not super cop but he is essentially a decent person. He is complicated and conflicted.

WERE YOU SURPRISED BY THE AUDIENCE’S REACTION TO THE FIRST SERIES?

We were all excited by the first series and hoped what we were making was a good show. There are a few times in your life, if you’re lucky, when people connect with something you’ve made in a way that goes beyond your dreams or what you could have wished for. I really believed in the show and felt it was a very good piece of work. It’s one of the most successful things I’ve worked on and I knew within reading the first five pages that I wanted to play this character.

WHERE DO WE FIND CHRIS IN SERIES TWO?

It’s six months on and Chris’ relationship with his missus is in a bad way. He loves his daughter, but his marriage is not in a good place. His relationship with his job is terrible and we join him at a point where he’s trying to help himself. In the first series, we saw him attending therapy sessions provided by the police service but it’s hugely underfunded so this time round he is attending his local church men’s group run by a priest, Father Liam. He’s trying to help himself and find some light.

IN SERIES ONE CHRIS CLAIMED THAT ALL HE WANTED TO BE WAS A GOOD BOBBY. WHAT DOES CHRIS ASPIRE TO BE IN SERIES TWO?

Chris wants to be a good dad and a happier person but he’s not in a good way and that’s at the heart of the story. It’s not all about Chris but we do see him experiencing different levels of stress, anger and regret. What Tony does brilliantly is let his scripts breathe and that’s my favourite thing about them. Rather than be too plot driven, the drama is story and character led and in series two we get to see more of the lives of the characters we came to care about in series one.

HOW HAS THE RELATIONSHIP BETWEEN CHRIS AND HIS FORMER PARTNER RACHEL CHANGED AND GROWN SINCE SERIES ONE?

Chris and Rachel’s relationship is thawing out a little now they’re getting a little bit closer. The battle lines between them are coming down a little bit and they’re a bit less spiky with each other. There’s a bit more air in their relationship now they can look at each other and go: “You’re all right, you’re a good person.” That doesn’t sound very dramatic, but it’s real. I like their relationship a lot for that and the fact they look out for each other, in their own ways.

When we first met them, Rachel doesn’t want to be mentored by Chris because he’s a mess. She’s just come out of college and she’s on probation and is still thinking she can do it by the book and Chris is in no doubt that you can’t do it like that. In series one they are at opposite ends of the spectrum, but in this series that has all changed. Chris is wanting to be better – a better dad, a better copper – but Rachel is deeply struggling and isn’t playing it by the book any more. So they are at the other ends of the spectrum.

The Responder returns to BBC One on May 5 at 9pm.