HBO’s Crazy, Not Insane asks the question: what makes a serial killer?

Serial killer statistics on the internet will rapidly lead you down a deep, dark rabbit hole.

Quick fact: a serial killer is one who commits a series (there it is) of murders, typically following the same or similar modus operandi; a mass murderer is one who kills a lot of people at one time in one place. The Encyclopedia of Public Health puts this figure at three or four in a spatial area but of course it can rise to hundreds of thousands, even millions, when you factor in genocide. Some believe there are around 50 serial killers roaming the US, others place it more towards the 4 000 mark, depending on your Google search. Heck, even one is scary enough.

As you can clearly see, it’s easy to get off topic. 

Crazy, Not Insane is an HBO documentary that examines the work of forensic psychiatrist Dorothy Otnow Lewis and her research into the psychology of some of the world’s most notorious killers.

Her work sparked controversy in the head-shrinking world – as well as among those who consider themselves crime experts – where not everyone agreed with her theories. These opposing views are expressed in this film, which is the mark of journalistic excellence: to tell both sides of the story (even though we’re obviously on Lewis’s side).

“Lewis’ work would place her on the stand as a defense witness where prosecutors would do their best to discredit her,” says Yale School Of Medicine. “It would even put her at odds with the mainstream of her profession as she challenged conventional theories that attribute violent behavior to socioeconomic deprivation and lax discipline.”

Yet Lewis would not be deterred. She devoted herself to the study of murderers, and in particular those she thought have or had dissociative identity disorder, formerly known as multiple personality disorder.

“She believed that many killers were not making up having an entity within them that instructed them to kill, including [Ted] Bundy,” says True Crime Buzz on Oxygen. “Her theories on multiple personalities have been controversial and, as noted in the documentary, she has often been the subject of ridicule because of these beliefs. Many of her claims have been challenged in court and she has been criticized for her seeming support of some of the most vicious killers in the world.”

Drawing on chilling videotaped footage of death row interviews and case studies, from Arthur Shawcross – who claimed among his personalities someone named “Bessie”, his mother’s name – to Ted Bundy, Lewis challenges the notion that murderers are born and not made. Or in other words, nature versus nurture – the argument as old as time itself. Lewis believes there are three pillars that form a foundation and occur consistently in the most violent offenders: brain dysfunction, child abuse and psychotic thinking, particularly paranoia.

“When all three occur simultaneously, Lewis believes, they become primary ingredients in a recipe for violence,” says Yale.

While every case has its own unique set of circumstances, that of Bundy is notable because he claimed to have come from a perfect childhood in a perfect home. The day before his execution, Lewis visited him in prison – at his request, in a last gasp attempt to stay out of the electric chair – and he made some startling revelations, whether genuine or not we will never know, that supported Lewis’s theories.

Clocking in at just under two hours, Crazy, Not Insane is asking a lot of our attention span but it’s never not fascinating, nor does it ever warm up above chilling as Lewis informs us we are always more interested in what the killer(s) did rather than what made them killers in the first place.

“The media obsession with serial killers receives a welcome infusion of academic analysis and sobriety,” says CNN. For those obsessed with the subject, this is essential viewing to add to the list.

The documentary is narrated by Oscar winner Laura Dern (Big Little Lies, Marriage Story) and written and directed by Oscar winner Alex Gibney (Taxi to the Dark Side, The Inventor: Out for Blood in Silicon Valley, Enron: The Smartest Guys in The Room and much more). 

If anyone had to play Lewis in a movie, it should be Cynthia Nixon. Change my mind.