Murderers – even serial killers – are made, not born. This is the thesis of new Crime+Investigation series Making a Monster, which offers a fresh take on the increasingly popular true-crime genre.

The series elicits the views of leading psychologists, interwoven with dramatic reconstructions, as it revisits the crimes of notorious killers, who include Rose West, Levi Bellfield and Aileen Wuornos.

“These cases have been talked about before. Often, in true-crime series, it’s the police investigators who are the contributors, but where do the police go when confronted by something like the horror of [Rose West’s house] 25 Cromwell Street?” said Dan Korn, VP for programming at A+E Networks UK, which runs the Crime+Investigation channel.

The police turn to forensic and criminal psychologists, some of whom – including the panellists at an RTS early-evening event in February – contributed to Making a Monster.

The erudite series began its eight-part run last month and is made by David Howard and Rik Hall for Wales-based indie Monster Films. It aims “to go beyond the shibboleths and stereotypes, and to treat the serial killer, to a certain extent, as a patient and to get inside that,” explained Korn.

Sunday Times Crime Club editor Karen Robinson interviewed the experts following the premiere of the series opener about the life of Gloucester mass murderer Rose West. It made for grim but illuminating viewing.

Criminal profiler Professor Paul Britton adopts a “very narrow definition” of “evil” in the context of serial killers. “For me, a person is truly evil if they come into the world with no deficits,” he said. “[This is a person] with a full cognitive, functioning background; their emotional development is normal. All of the things are as they would be for most people.

“Nevertheless, they find their pleasure is in harming, hurting, being cruel to other people.… That, for me, is true evil, where there is that clear choice. Most of the others behave in an evil way but, when you look, again and again you see the deficits.”

However, Britton added: “It is important to recognise that thousands of youngsters come from dysfunctional backgrounds and they do not all end up in this situation. Just because a youngster was offended against, does not mean that, in turn, they will then offend.”

The programme-makers secured the involvement of University of Leicester forensic psychologist Dr Julian Boon by assuring him that there “would be nothing salacious or gratuitous” in the series. Making a Monster, said Boon, “dispels the myth that there is something like a generic serial killer. Each one has to be painstakingly understood with regard to their own individual circumstances and how that expresses itself in terms of criminal activity.”

Dr Samantha Lundrigan, an investigative criminal psychologist and specialist in geographic profiling at Anglia Ruskin University, said: “The series offered the opportunity to “take the [true-crime] genre in a different direction and get under the surface of these well-known offenders.

“I did ask myself at the beginning, ‘Is there any more that can be said about these people?’ My answer was yes, because [the series]… tries to understand the science underneath and look at some of those techniques, such as geographic profiling, that haven’t been looked at before.”

"I wonder if, when people are running, they think about body disposal sites? I do"

Lundrigan said that she “grew up on a diet of true-crime documentaries and books – it’s what took me into the field I’m in.… I always thought I’d be [The Silence of the Lambs character] Clarice Starling, but I’m still waiting.”

The psychologist confessed that she had been “disappointed” with some of the previous true-crime series she had been involved with: “[They were] salacious and graphic, sometimes unnecessarily so, focusing entirely on the crime of the offender and not giving a voice to the victim. This has been a different experience.”

Britton, who is a professor at Birmingham City University, noted that “there is so much that you still can’t say – the things that happened are so appalling”. He argued that TV programmes had to find a balance, and not “shock people so much that they are unable to… see in the life stories of these offenders [something] that alerts [viewers] to what may be going on close to them”. In particular, [people should consider]: “Is there a time when I should pick up the phone [to the police], even though I feel uncomfortable or embarrassed?”

Referring to Rose and Fred West’s victims, he said: “There are other young women who haven’t been found yet. If something can move it forward so that just a few more families know of their loved ones, I think it’s worth it.”

The Wests’ crimes, suggested Robinson, were “particularly horrifying” because they happened in what appeared to teachers and social workers like a family home.

“For this couple, family life and criminal life were inextricably linked – you couldn’t separate them,” replied Lundrigan. “The house… looked quite normal but what was going on behind closed doors was unfathomable. If they had never got together, I’m sure [Rose] wouldn’t have gone down this path.” The psychologists agreed that serial killers were incapable of remorse for their crimes. “Unless they come up before the parole board – which none of this lot [in the series] will,” said Boon. “Remorse is not something they can genuinely get.”

Britton expanded on this: “Most of them don’t have the capacity to feel [remorse]. It’s simply not there. Whether it was ever there, is an interesting question. And, if it ever was, then how it became lost is an interesting exercise and probably the subject of an entirely different programme.”

Viewers can turn off the TV if the crimes are too egregious, but criminal psychologists are at risk of taking the horror of their work home with them.

“I am always aware of my environment, because I look at where crime happens,” admitted Lundrigan. “I run a lot in the countryside… I wonder if, when people are running, they think about body disposal sites? I do. I’m always evaluating my environment.”

“When you are involved in any of these cases, you don’t bring it home with you – but you leave a bit of yourself behind,” said Britton. “You end up slightly diminished by what you’ve been involved in. I’m fortunate that this work is only a part of [what I do]. I’m an NHS clinician by origin, so [my job is] also helping people to get better, understanding what’s wrong with them and being able to discharge ­people who are now better, rather than who are going off to spend the rest of their years in prison.”

Looking back at Making a Monster, Britton believes that the series has avoided “giving a guidebook to potential serial killers in how not to be caught. That’s important and I don’t think we’ve fallen into that [trap].”

And, added Boon, the programme has also avoided romanticising the killers or their crimes: “You only have to look at the episode about Bellfield to realise just how unglamorous a figure he is.… [The series] is not leaving people with any illusions to the contrary.”

Report by Matthew Bell. ‘Making a Monster: Screening and Q&A’ was held at the BFI in central London on 4 February, and produced by the RTS and A&E Networks UK.