Judging by the packed auditorium at tonight’s Funzing talk, I’m not the only person who is fascinated by serial killers. Where, exactly, is the dividing line that separates them from us – and what causes them to cross that line?

FBI profiler Paul Harrison has spent decades trying to answer those questions. Harrison is a former Metropolitan police officer who worked with the FBI’s Behavioural Unit for many years interviewing some of the world’s worst killers: “Not an easy job”, he remarked, wryly. Inevitably, this meant spending a lot of time at America’s Death Row which is, Harrison says, nothing like what’s presented on TV. Rather, it consists of a series of prisoners sat on their beds looking blankly into space “like human zombies switched off”. Death Row is, he says, a “horrible, cold place”.

An added challenge for any profiler is that convicted serial killers don’t necessarily want to talk. They are under no legal obligation to do so, and some “put up a brick wall”. Nonetheless, “As an FBI investigator you’re committed to getting them to share as much information as possible – and to getting into their mindset”.

There is no answer, mused Harrison, as to what creates a serial killer. The few things that we have learned about them invariably link back to childhood and to a lack of morals and/or discipline.

Charles Manson

In no case is that more true than that of Charles Manson – who needs no introduction. The repercussions of the murder of a pregnant Sharon Tate and five of her friends continue to confound decades later; it’s hard to imagine a more horrific way in which to die. Harrison had not expected to interview Manson – had been warned, indeed, against doing so: “He’s too clever; he gets inside your head”. Manson, however, was keen to talk.

“I was dreading it”, Harrison recalled. “My colleagues were all shaking their heads and showing me footage of Manson reacting to interviewers, sticking his tongue out and behaving bizarrely”. Reacting, in other words, to media pressure to be a weirdo.

In the flesh, it was a different story. Manson, far smaller than Harrison, smiled and said “Hi, how are you? I don’t know what to expect”. “Neither do I”, responded Harrison – at which Charles Manson launched into a personal diatribe that didn’t stop. Exasperated, Harrison stood up and told his erstwhile interviewee that he was leaving – at which point Manson came running round to his side of the table, shouting “Why are you going?”

Taking a deep breath, Harrison told Manson, “I just want to understand who Charlie Maddox [Manson’s real name] was. I want to stop future generations from taking your path. You can leave a legacy”.

Harrison had found a chink in Manson’s armour – and the latter calmed himself down. The duo went on to have some “relatively normal” conversations, which provided Harrison with useful insights. It was talking about his mother that fired up Manson, whose childhood was unedifying, to say the least. “She was a bitch, wasn’t she?” confided Manson. “If she’d taught me the good things, my life could have been different. I could’ve been doing what you’re doing”.

When it came to terminating the interview, Harrison didn’t know what to do. Should he shake hands? Wave? Taking him by surprise, Manson threw his arms around his waist, crying “I’ll see you soon!” Disentangling himself, Harrison replied, firmly: “No, you won’t, Charlie”.

Manson, Harrison reflects, was an “arrogant, bad soul”. But “you need to poke into the dark aspects of the soul to understand him – and others like him”.

Peter Sutcliffe

The same might be said of Peter Sutcliffe, known to most of us as the ‘Yorkshire Ripper’. The man – and the way in which he was fěted – are unbelievable. This is an individual who did not see the sex workers he killed as human beings. Yet, once caught and housed in Broadmoor, he was treated like a celebrity. Jimmy Savile, who for some inexplicable reason was handed the keys to Broadmoor, used to take his celebrity friends there – which is how poor old Frank Bruno ended up having his photo taken with this most gruesome of serial killers, having been informed that this was the man who cleaned the toilets.

You couldn’t make it up, could you? Once in the prison system, Sutcliffe became a celebrity in his own right, with many of the prison wardens giving him special treatment. And yet, Sutcliffe has refused ever to apologise to any of the families of his victims.a

Aileen Wuornos

Heading back across the pond, we encounter Aileen Wuornos, one of the few known female serial killers. Her crimes were horrific and it’s hard to empathise with her – but she provided the FBI with a comprehensive list of the offences against her, together with their times, places and perpetrators and it was evident to Harrison that she felt very alone. Certainly, her life reads like a cautionary tale: sleeping rough at six years old, she was abandoned and ignored. At her trial, the one place you would have expected to find someone on Wuornos’s side, her own defence lawyer sold the rights to her story (later to become the film ‘Monster’) before the trial had even ended.

You may recall that Wuornos, exhausted, eventually requested that her trial be moved forward and relinquished her right to appeal. At this point, Harrison told us, Wuornos needed her lawyer to argue, on her behalf, that she shouldn’t be executed – but no-one stepped forward. The situation, he recalls, was “like a railway train gathering momentum” and he recommended that we watch Nick Broomsfield’ documentary ‘Aileen: Life and Death of a Serial Killer’. Ultimately, Wuornos was silenced “because of her truth”.

Far less sympathy was evinced towards John Wayne Gacy, Harrison’s first-ever interviewee, who believed Harrison to be vulnerable. The latter, nonetheless, learned a lot from this killer of 33 people who, aged just 12, became a Peeping Tom: “a power that did not satiate his desires”.

It was complacency that brought about Gacy’s downfall: he began burying bodies under his house, and neighbours reported the smell. Under arrest, he told Harrison that he’d “never hurt a soul – but the clown might have”. Unimpressed, Harrison describes this “very manipulative character” as a coward who killed many more people than he admitted. Chillingly, he told Harrison that, when the FBI profiler died, he’d be waiting by the Pearly Gates for him.

Joanne Dennehy

There is always an exception to the rule – and Joanne Dennehy is most definitely that. She is, unenviably, a rarity in the UK, having shattered our preconceptions about serial killers by killing at least three men. By coincidence, Harrison had a conversation earlier today with ITV, who are considering making a documentary about Dennehy as a victim in her own right. This jars with Harrison, who knows that she came from a functional middle-class family with parents who gave her everything she wanted (indeed, her older sister has had a glittering career in the Armed Forces).

And this is where it’s difficult to join up the dots: 98% of murderers come from a dysfunctional background, from which they learned behaviours that they adopt into their own lifestyle.

What we see with every killer is that, says Harrison, is that each crime becomes slightly more dull; their behaviour deteriorates while they urgently seek out excitement. Dennehy was believed by her school teachers to be “academically brilliant” – and yet, for some inexplicable reason, aged 13 battered the school bully. Asked to explain herself, she answered that she was “bored of being normal” and was promptly forgiven; while the bully was excluded from school, the teachers apologised to Dennehy.

“Weak” is how Dennehy perceived those teachers and she was soon dating a boy four years older than her and involved in petty crime. Her family tracked her down and brought her home, rewarding her with love  and doing their best to block out what she had done: understandable, but misguided, believes Harrison.

By now, Dennehy was indulging in alcohol & drugs and getting away with it – and was “on a path with no respect for anyone”. Of course, this is a complex story. Dennehy believes that all the male figures in her life abandoned her – and she has accused some of them of using her sexually and “pimping her out”. Conversely, the women Dennehy had sex with she believes understood her – while the men walked away and became her demons.

Dennehy’s crimes worsened as her need for alcohol & drugs increased and she told her family that she didn’t want anything to do with them. However, she gives the lie to the argument that serial killers murder animals: the opposite is true. Dennehy adored dogs and had an addiction to animals in general; in fact, she stabbed someone she believed she’s seen kick their dog. Harrison managed to track down that individual, who told him that he had swung the dog around because he’d thought Dennehy was going to attack it.

Joanne told Harrison that she hated being “too nice”. She desperately wanted to be remembered for a different reason – and woe betide anyone who was cruel to animals. However, she didn’t mind killing humans because she didn’t see them as her equals.

Joseph Roy Metheny

Joseph Roy Metheny was another individual who Harrison was advised against approaching: “He’s bad”. As tall as he was broad, JRM stood at 7 foot tall. Harrison found him “terrifying” yet in possession of a “comforting” voice. “I do not want to be someone who’s infamous”, this murderer told Harrison. “I’ve killed 12 people, but I don’t want anyone saying I’m special”.

Under no illusions, Harrison noted how Metheny wanted to be in control of every aspect of prison life – and his black, “shark-like” eyes. His size was intimidating, our profiler says, and if he got angry with you, you’d never escape – yet he came across as desperate to talk, accusing the FBI agents of not wanting to understand him.

It’s so difficult to know how to feel about this giant of a man, who claims to have been ostracised from birth because of his size and who, from the age of eight, was an effective pugilist who hospitalised one of his teachers. Yet, he served in Vietnam with distinction, where his colleagues loved him and viewed him as a “gentle giant”.

But, two years after leaving the army he was beating up his girlfriend and committing other acts of violence which Harrison deemed too distressing to share with us.

The behaviour of a serial killer doesn’t stop with the individual. How might it influence their children, and any other generation? According to Harrison, the offspring of these criminals are given a greater level of support in the U.S. than you’d find in the U.K. – and are closely monitored. Consistent “red flag” behaviour is reported to a supervisor by a teacher, with police the last resort. Every effort is made to understand the infrastructure and dynamics surrounding the individual in question.

I found Paul Harrison to be a sympathetic speaker on an incredibly complex topic. Whether we will ever really understand the behaviour of the individuals talked about in this post, I’m not sure – but I’m thankful that the likes of Harrison continue to try; if we only glean just a little understanding, we surely move a little closer to preventing these horrific crimes from happening again.