Why Did They Do it? Inside the Minds of Australia’s Most Unlikely Killers

Here’s a terrific book for readers who are interested in analysing personalities and their motives, especially where a crime is involved. An investigative journalist and a psychologist have here collaborated to write a book revealing reasons for murders committed in Australia over our more recent past. There’s Kathryn Knight, for instance, who stabbed and skinned her partner with the intention of serving his cooked body to his children, Peter Caruso who bashed his wife to death after almost fifty years of seemingly happy marriage, and eight murderous others. All of their cases have been on the public record, making headlines all over the country.

Why did these people kill (usually loved ones)? Motives differ in each case, but co-writer McGrath shifts most of the blame on personality disorders that all of the killers suffer from. She is at pains to point out that personality disorder is not a mental illness; instead it is a mental disorder (such as avoidant, narcissistic and antisocial borderline personality disorder). All the killers in this book have problems with appropriate response, interpersonal relations and impulse control. People with personality disorders have difficulty dealing with everyday stresses and problems; under stress they try to control an outcome which can lead to an interpersonal crisis – and sometimes to committing hideous crimes.

Of great interest, especially in the book’s introduction, is an insight into the effects of parenting styles; later, as each murder case is analysed, the reader learns about each killer’s childhood, how they were parented and how their life experiences led them to commit the crimes that stunned the nation. In the body of the book, the journalist and the psychologist dissect the crimes, the evidence, the testimony, the confessions and the overwhelming diagnostic evidence to analyse the minds and motivations behind the murders.

The setting out of each chapter is different from the usual, starting with a cast list of those involved in the crime – victims, murderers and relatives and friends. Sub-headings include motive, lead-up to the crime, the murders, the sentencing and the perpetrator’s background. Following this is a diagnostic chart with DSM 5 indicators such as that used by psychologists and psychiatrists when diagnosing mental disorders (and mental illness). Then there’s a timeline of key events. The authors have worked hard – and succeeded – in trying to make the book comprehensive, and yet the whole is easily accessible to any curious lay-person. At the conclusion of each part of the book is an oversight into what we can learn from the murders committed – say, for example, by Robert Farquharson (who drowned his three small sons as an act of revenge against his wife) and John Myles Sharpe (who murdered his small daughter and his wife because she was pregnant and he couldn’t cope with the thought of another child).

In most of the cases written about here, the perpetrator is generally described by people who knew them as average, ordinary or normal. But, as the book reveals, they all carry the burden of disorder. Words to describe Why Did they Do It? Fascinating, well-researched and documented, highly readable, and recommended if you can stomach what some people will do some of the time. 

Reviewed by Di Bates

Title: Why Did They Do it? Inside the Minds of Australia’s Most Unlikely Killers
Author:  Cheryl Critchley and Dr Helen McGrath
Publisher: Pan Macmillan
Publication Date:  August 2015
RRP: $32.99
Format: Paperback
ISBN: 9781743533178
Type: Non Fiction - True Crime