‘You might say that I am a student of evil’

Forensic psychiatrist and psychotherapist Dr Gwen Adshead explores our ‘shadow side’

You might say that I am a student of evil. I work as a forensic psychiatrist and psychotherapist with people who have committed crimes of violence, usually when mentally unwell, and this has been my work for over 30 years. In The Devil You Know, the book I have co-written with Eileen Horne, I invite readers to enter my world of work in prisons and secure psychiatric hospitals such as Dublin’s Central Mental Hospital or Berkshire’s Broadmoor.

We portray a wide range of people, among them serial killers, stalkers, child sex offenders and arsonists. Their stories can sometimes be painful and uncomfortable, both to say and to hear, but there is nothing gratuitous or sensational about these accounts. The focus is on the work of therapy and the possibilities for changing minds, however troubled they may be. Their stories might help bring some sense to the senseless while revealing the fascinating complexity of the mind and our shared humanity with those our society often calls “monsters”.

In the process I realised that although every patient’s story is unique, there were several recurring concepts about the nature of evil and the reasons why people become violent that run through all these cases. These are some of the themes at the front of our minds as we wrote.

Evil is a state of mind

anyone can enter

We all have a “shadow side” that may be hard to see, but it is human to resist this idea and cling to the notion that evil is both obvious and only found in “others”. This kind of denial can be dangerous. Lydia was a patient who might have been mistaken for a colleague or a friend. Around my age and of similar background and education, she appeared genuine in her regret about what she termed one error of judgment that led to a conviction for stalking her former therapist.


When we met, Lydia was transitioning from prison back into the community. She spoke of her offence like an unfortunate misstep, a trip not a fall. I had a vague sense of something amiss, but her conversation about things familiar and unremarkable, like her fondness for gardening and dogs, managed to obscure the fact she had not let go of her deadly obsession. Taking her at face value taught a hard lesson about making assumptions and heeding my instincts.

Evil is ordinary

Writing about the Nazis, Hannah Arendt famously used the phrase "the banality of evil". I've found this to be accurate, but it is an idea that may not sit comfortably with consumers of lurid true crime or violent thrillers. People seem to prefer their baddies to be obvious demons or weird loners who signal their cruel intent in telling quirks of appearance or affect. I have come to think of evil rather like beauty; it is formed in the eye of the beholder.

I still remember feeling baffled when a prison officer once told me that the patient I’d come to meet “looked like a nonce” (using prison slang for a sexual offender). I’d met with hundreds of sex offenders, and they had no common characteristics other than being primarily male, which is true of offenders in general. In the book, I describe David, an English family GP who seemed like anyone you might sit next to at a suburban dinner party or see for advice about a nagging ear infection. He couldn’t have presented as more “ordinary”, yet his offence, involving violent child pornography, was beyond most people’s comprehension or experience.

Minds can change

I wouldn’t have stayed in this job for as long as I have if I did not feel hope or see evidence that therapeutic and medical interventions could change minds. Violence perpetrators are not born with a propensity for evil, and I think none of us should be defined by one act, no matter how heinous; we humans are far too complicated for that. There is something inhumane about that fact that (as one of my patients once observed) “you can be an ex-bus driver, but you’ll never be an ex-murderer”.

Different metaphors for the mind arise over time in literary and scientific circles, reflecting ideas of their era. Today the computer is favoured: the mind as a machine, slipping into “default mode” and “processing” human experience as “data”.

I prefer a different analogy, something organic and dynamic: I imagine the mind as a coral reef, as dark as it is life-enhancing and full of beauty. These complex systems are both capable of repair, but only if we make it an urgent priority. I met with a young woman called Sharon three times to assess her state of mind for the family court. She had twice had her children taken into care because she was considered a risk to them.

Over several years, I witnessed a remarkable transformation in her once she got help and was willing to talk about past trauma; eventually, this meant she could keep and care for her third baby. Outcomes are not always this positive, but minds can and do change for the better if the person is willing, and open to “a deep dive”.

Survivors and disasters

A young man called Sam was allowed out of a psychiatric unit and made his way to his parents’ home unannounced. In a therapy group I ran for people who had killed family members, Sam described how he reacted with fatal violence when his alarmed father appealed to him using a childhood nickname.

As Yeats would have it, Sam felt “choked with hate”, and tragedy resulted. I often describe my patients as “survivors of a disaster where they are the disaster”. Some people reject this construct because it suggests that the identities of victim and perpetrator can overlap. Some will never be comfortable with the idea that violent offenders deserve care and attention and think any treatment is a waste of time. But to understand violence and try to prevent it, we have to get up close and learn how and why it happens. There are benefits for everyone if there are fewer dangerous people in the world. If one of my family, or I, were ever to cross the line into an evil state and do something like Sam did, I would like someone like me to be on hand to help.

The bicycle lock

Over the years, I’ve come to picture violence as being contained in the mind by a psychological “bicycle lock”, which only opens when the correct combination of risk “numbers” click into place.

The most typical risk “numbers” for violence around the globe are young and male; women (of any age) are responsible for less than 20 per cent of all violent crime. Even so, in our book, we deliberately chose to have a gender balance, partly because I’ve spent years working with women. Female violence has long been distorted and misunderstood, and I wanted to challenge some theories and myths.

Kezia’s victim died of multiple stab wounds; Charlotte’s crime involved a brutal act of gang violence. Their methods and types of offending, as well as their histories of childhood adversity, could just as well be those of men. A key difference is that women’s violence tends to emerge later in life, suggesting it takes more for them to “unlock” that capacity.

Risk factors beyond age and gender, in order of statistical importance, are intoxication by drugs or alcohol; being generally antisocial and/or previously criminally violent; social isolation; exposure to high levels of childhood adversity; or experiencing paranoia due to any cause.

Not every violence perpetrator will have all of these factors, or they may live with one or more for years without harming a soul until a final factor comes into play. That last “number” tends to be idiosyncratic; a seemingly innocuous action, a glance or a phrase that has meaning only to the perpetrator. I’ve also seen how there are important protective factors against violence, including fostering pro-social attitudes, education, and social relationships – any of which can allow someone to transform their pain instead of transmitting it.

Mind and body

A young woman called Zahra burned down the flat where she lived in a suicide attempt in which other people were frightened and badly injured. She got a lengthy prison sentence for arson, and I met with her a few years later after a similar attempt when she set a fire in her cell.

I found her life story a sorry example of how our overstretched mental health services tend to offer too little too late – and how we undervalue the mind over the body in our society, inside and out of our prisons. Someone’s wounds or burns may quickly and successfully be treated, but mental scars often will not get the timely close attention that we know promotes repair. If Zahra had been given some therapy at 17, the first time she set her bedroom alight, her story might have been very different.

Perhaps the most crucial lesson is that the journey that leads to places like prisons or secure hospitals is not inevitable. These stories offer insight into our darker places and provide moments of hope; Zahra and many other people I have worked with were able to change their minds, however subtly or slowly. There are always opportunities for rescue and repair that can change a human path if we only recognise them. Rebalancing and investing in both the mental and physical in our healthcare and penal systems should be the great priority of our time; the benefits for all of us could be priceless.

The Devil You Know: Stories of Human Cruelty and Compassion by Gwen Adshead and Eileen Horne is published by Faber.