The psychological phases of a serial killer

An overview of the typical psychological phases of a serial killer observed by criminologists and psychologists, with reference to the Scottish serial killer Peter Tobin.

The process of serial killing typically follows a series of psychological and behavioural phases. While the exact progression can vary among different serial killers, criminologists and psychologists have identified common phases that many serial killers go through. Here at the Scottish True Crime blog, I take a look at the typical phases observed in serial killers with reference to convicted Scottish serial killer, Peter Tobin.

Born in Johnstone of Renfrewshire, Scotland, in 1946, Tobin's criminal activities came to light after his arrest in 2006 for the rape and murder of Angelika Kluk, a Polish student who had been staying in a room in St Patrick’s church where Tobin volunteered. Subsequent investigations linked him to the murders of Vicky Hamilton and Dinah McNicol, both of whom disappeared in 1991. Their bodies were found buried just metres from each other in the garden of a house Tobin had lived in at the time of their disappearances. His modus operandi involved gaining the trust of his victims before subjecting them to extreme violence and sexual assault, ending in their deaths. Tobin died in October 2022 in hospital chained to a bed and alone. No one came forward to claim his remains and so he was cremated and dumped at sea by Edinburgh City Council.

Lets take a look at the psychological phases of a serial killer:

1. The Aura Phase

This initial stage involves intense fantasies and obsessive thoughts about committing murder. The killer may become increasingly preoccupied with violent imagery and develop elaborate fantasies that fuel their desire to kill. Tobin had a history of violence and sexual offences. Former partners later reported on his violent, controlling and dominant nature. Of note here is an account of his first wife who he first met when he was 22 and she was 17. She has spoken of a time when she returned home to find that Tobin had decapitated her pet puppy. She was then raped and sexually assaulted with a knife. This account suggests Tobin had a long standing preoccupation with extreme violence.

2. The Trolling Phase

In this phase, the killer begins to actively seek out potential victims. This might involve frequenting certain locations, such as bars, parks, or neighbourhoods, where they believe they can find suitable targets. The killer is essentially "hunting" for a victim without yet taking direct action. The last sighting of Vicky Hamilton was at a bus stop opposite Bathgate police station as she waited for a bus back to Falkirk after visiting her sister. Trolling bus stops for potential victims has been seen before in the behaviour of serial killers such as Levi Bellfield who was even nicknamed “The Bus Stop Killer”. He was eventually convicted for the murders of Marsha McDonnell, Amelie Delagrange and Millie Dowler and the attempted murder of Kate Sheedy in the early 2000s. Many of these women were attacked on their way home from a night out. Amelie Delagrange had just got off a bus before being attacked in Twickenham Green while it is thought Millie Dowler was abducted at a bus stop near to a house Bellfield had access to.

3. The Wooing Phase

During the wooing phase, the killer attempts to gain the trust of their selected victim. This could involve engaging in conversation, offering assistance, or creating a false sense of security. The goal is to lure the victim into a vulnerable position. Was Vicky Hamilton offered a lift from Tobin as she waited for her bus? We know that Dinah McNicol, along with a friend, accepted a lift from Tobin after she had attended a music festival. During the trial for Dinah’s murder, her friend had recalled the conversation with Tobin. According to the witness, Tobin had commented on the music festival they had just attended stating, “It wasn’t his scene” and that he much preferred a different festival nearby. Criminologist Professor David Wilson believes this was Tobin’s attempt at putting his potential victim at ease by acting socially superior in their prescience.

4. The Capture Phase

This stage involves the actual abduction or physical restraint of the victim. The killer's fantasies are now becoming reality as they exercise control over the victim, often using manipulation, deceit, or physical force. Accounts from former partners confirm Tobin exerted both physical and psychological control over his victims. There is no doubt that Tobin would have used whatever physical force was necessary to restrain his victims in this phase.

5. The Murder Phase

The murder itself takes place in this phase. The method of killing often reflects the killer's fantasies and can include various forms of violence, such as strangulation, stabbing, or shooting. The act of murder provides the psychological release or gratification the killer has been seeking. Angelika Kluk was reported to have been “bludgeoned” to death with a wooden table leg and stabbed 16 times before being wrapped up and dumped under the floor of the church where they were both volunteering. Senior Forensic Scientist, Carol Weston, who examined the scene later said Angelika had a “very violent death”.

6. The Totem Phase

After the murder, the killer may engage in rituals or take "trophies" from the victim. These trophies can be personal items, body parts, or photographs that serve as mementos to relive the crime and sustain the killer's fantasies. Following Tobin’s conviction for the murder of Dinah McNicol, police released images of women’s jewellery they had found in Tobin’s possession. They believed he had kept trophies from unknown victims despite a later investigation known as ‘Operation Anagram’ failing to link him categorically to any other murders. Among the 37 items recovered were watches, necklaces, diamond rings and a black leather purse.

7. The Depression Phase

Following the murder, the killer may experience a period of emotional let-down or depression. The euphoria from the killing fades, leading to feelings of emptiness or guilt. This phase can be relatively short-lived as the killer's fantasies and desires resurface, starting the cycle again. Tobin exhibited no remorse or guilt and maintained a defiant attitude throughout his trials and time in prison. He is suspected to have murdered many more woman across the country and is reported to have admitted to a cell mate that there are “more bodies”. As we will never know the true extent of Tobin’s crimes, accurate identification of any depression phase is unlikely.

Considering the psychological phases of a serial killer provides a framework for understanding their behaviour by helping to illustrate how their fantasies, methods, and psychological states evolve throughout their life. Ultimately this can help law enforcement apprehend and hopefully treat serial killers. This analysis of Peter Tobin has shared strong examples at every phase showing that Tobin’s behaviour followed a classic serial killing pattern.

This article is intended to be educational. While the focus is on the behaviour of the perpetrator, please know that the victims and their families haven’t been forgotten. As such I’d like to recommend to you ‘The Victim’s Voice’, a newsletter dedicated to hearing stories about and remembering the victims of true crime.