
Last year, I was invited to contribute to the series ‘World’s Most Dangerous Prisoners’ which looks at offenders whose shocking crimes earned them a whole-life tariff behind bars. Tonight’s episode focuses on Joanna Dennehy who fits the generally accepted definition of a serial killer having committed three calculated and brutal murders with a ‘cooling off’ period between the killings (Farrell, Keppel and Titterington, 2011). Having developed a taste for killing, Dennehy then attempted to murder two random strangers.
Women who commit serial killings are rare and research into victim relationships and motivations lags male offenders (Farrell, Keppel and Titterington, 2011). My aim in this blog is to reflect on my involvement in this infamous case and briefly highlight some of the keys to success as well as exploring why Dennehy will never be released from a life behind bars.
The Investigation

This major Investigation began on Saturday 30 March 2013 after Cambridgeshire Police discovered the body of a man who had been reported missing. The body had been staged in what could be considered an act of humiliation. A murder investigation was commenced, led by a Senior Investigating Officer (SIO) Martin Brunning of the Bedfordshire, Cambridgeshire, and Hertfordshire Major Crime Collaboration Unit. Unknown to Martin at that time, Dennehy had already killed two other men.
By this time, Dennehy and her accomplice Gary Stretch were already on the run. On 2 April both made their way to Hereford in the West Mercia Force area where Dennehy told Stretch that she wanted to kill again: “I want my fun… I need you to get my fun” (Cawley, 2014). Dennehy specifically requested that Stretch find male victims, not women or children. Stretch then drove around Hereford where Dennehy stabbed two men out walking their dogs in random separate attacks within 20-minutes of each other. Both men were callously attacked from behind and the injuries inflicted were horrific. In the second attack alone, the victim suffered 30 stab wounds. Miraculously both survived despite suffering near fatal injuries and I was appointed as the SIO for this investigation.
Success factors and the crucial role of First Responders

We teach our UWE Police apprentices that the key to success for investigations largely lies in ‘making the right decisions, taking the right action and securing evidence’ (Cook and Tattersall, 2014, p. 64) by following the ‘golden hours’ principle. You often only get one chance to get things right.
For many of the response officers involved, this will have been one of the most important incidents they will have dealt with in their careers. Through their rapid and professional response, Dennehy was captured near to the scene of the second attack in Hereford in what was a dramatic moment for the investigation. Stretch was also quickly arrested some miles away following an extensive manhunt. I firmly believe that the actions of the responding officers prevented further attacks. What they did was get the building block principles, including:
- The priority and fast response to protect life.
- Preservation of the two attack scenes north and south of the river Wye which dissects the city.
- Securing evidence and initial accounts from victims and key witnesses.
- Identification of the victims.
- The first victim was able to describe their attacker as a woman with a distinctive star tattoo on her face and Dennehy was identified as the prime suspect. An area search quickly resulted in her arrest and recovery of Archie the dog stolen from the second Hereford attack victim. The significant statement made by Dennehy admitting to killing ‘him’ was recorded.
- The arresting officers also recovered other key evidence including a blood-stained knife and clothing. A search of the vehicle resulted in the seizure of a camera bizarrely containing photos taken by Dennehy and Stretch in the days leading up to the attacks.
It was only on the day following her arrest that the true extent of her killing spree became apparent with the discovery of two further murder victims in Cambridgeshire. In common with research on female serial killers, all the Cambridgeshire victims were known to Dennehy (Hickey, 2015) and were stabbed to death and callously dumped in ditches in what came to be known as the ‘Peterborough Ditch’ murders. By contrast, a distinguishing feature of the Hereford attacks were that they were committed on strangers with no apparent motive. Dennehy had clearly developed a ‘moreish’ taste to kill (Judiciary of England and Wales, 2014, p.18).
Teamwork
It was agreed that I would take primacy for the joint investigation due to having the greatest chance of successfully resolving the case. In the glare of significant public, media, and organisational attention, the pace of investigation was intense and effective cross border working between forces was essential. Both Martin and I worked hard in these initial stages to find practical solutions to the problems and challenges that arose. The joint working between our teams and effective sharing of information enabled us to maximise evidence gathering. As the pace slowed and primacy for the joint investigation passed over to Martin and his team, we formalised this joint working in a Memorandum of Understanding which was crucial in maintaining focus on the main lines of enquiry and building a successful prosecution case. The professionalism in handling of the case later drew significant organisational and media praise (Knight, 2014) which the whole team was proud of.

Sentencing a serial killer

Dennehy was convicted of the three murders and two attempted murders in February 2014. She was the first woman sentenced by a Judge to serve a whole-life term (Judiciary of England and Wales, 2014). In 2023, Lucy Letby became the second female serial killer sentenced by a Judge to a whole life term (Thomas, 2023). The only two other women in English criminal history to be assessed as so dangerous never to be released were Myra Hindley and Rosemary West who instead were ordered not to be released by the then Home Secretary.
Dennehy was not a sophisticated criminal who was used to concealing evidence and actions from the police. Dennehy’s actions were however, shocking not only for their brutality, but also because female serial killers are relatively rare, only accounting for 15% (Farrell, Keppell and Titterington, 2011). This rarity, combined with the extreme violence of Dennehy’s crimes, has contributed to her notoriety and the international media attention surrounding her case.
As well as having a professional interest in crime investigation, I also have an academic interest in the theories and principles central to criminology and criminal psychology having competed a MSc in this subject. Before the Dennehy case I remember one of my assignments being titled ‘Do real psychopaths exist’. We do not have the time to go in-depth on this, but it is interesting to compare the Dennehy case with some psychopathy traits:
- The interpersonal traits of a psychopath include ‘superficial charm…and the manipulation of others’ (FBI, 2005). Dennehy clearly exercised control and manipulation over men in her life. Dennehy also sought to regain control at trial by pleading guilty to the surprise of her Defence team (Cawley, 2014). The Judge in sentencing Dennehy commented that she was a ‘…manipulative serial killer’ (Judiciary of England and Wales, 2014, p.1).
- Sentencing comments also showed how the murders involved ‘sexual and sadistic conduct’ and that Dennehy saw the killings as a kind of fetish. Research indicates that ‘violence and sexual gratification are inexplicably intertwined’ in serial killers’ motivations (FBI, 2005).
- Another psychopathy trait is lack of remorse or guilt. Mr Justice Spencer made it clear that Dennehy had ‘shown no genuine remorse’ (Judiciary of England and Wales, 2014, p.18).
- Research also shows that psychopaths ‘are extremely callous in their interactions with their victims’ (FBI, 2015). The surviving victims of the Hereford attacks both recounted how Dennehy was so cold, cruel, and calculated, showing no emotion other than wanting to stab them some more (Cawley, 2014).
- Another common trait is sensation seeking (FBI, 2005). Dennehy was said to have revelled in the notoriety of being Britain’s most wanted person and whilst on the run, compared herself and Stretch to the US robbers Bonnie and Clyde (Cawley, 2014).
These traits along with the heinous nature of her crimes explain why Joanna Dennehy will never be set free. You can find out more about the Dennehy case by watching the ‘World’s most Dangerous Prisoners’ on 5Action at 9pm tonight. It is available to watch on SKY (current channel 150) Virgin (current channel 130) and Freeview (current channel 33), and Channel 5 on demand service My5.
References
Cawley, L. (2014) Joanne Dennehy: The woman who murdered men ‘for fun’. BBC [online] 12 February 2014. Available from: https://www.bbc.co.uk/news/uk-england-25669206 [Accessed 22 January 2024].
Cook and Tattersall (2014). Blackstone’s Senior Investigating Officers’ Handbook (3rd Ed.) Oxford University Press.
Farrell, A. L., Keppel, R. D., & Titterington, V. B. (2011). Lethal Ladies: Revisiting What We Know About Female Serial Murderers. Homicide Studies, 15(3), pp. 228–252. [Accessed 22 January 2024].
Federal Bureau of Investigation (FBI) (2005) Serial Murder: Multi-Disciplinary Perspectives for Investigators. Behavioural Analysis Unit National Center for the Analysis of Violent Crime. Available from: https://www.fbi.gov/stats-services/publications/serial-murder [Accessed 22 January 2024].
Hickey. (2015). Serial Murderers and Their Victims (7th edition.). Cengage Learning.
Judiciary of England and Wales (2014). The Queen ‐v‐ Joanne Christine Dennehy Gary John Stretch Leslie Paul Layton Robert James Moore In the Crown Court at Cambridge sitting at the Central Criminal Court 28 February 2014 Sentencing remarks of Mr Justice Spencer. Available from: https://www.judiciary.uk/wp-content/uploads/JCO/Documents/Judgments/the-queen-v-dennehy-sentencing-remarks-28022014.pdf [Accessed 22 January 2024].
Knight, A. (2014) Top Cops praised for serial killer snare. Hereford Times [online] 29 October 2014. Available from: https://www.herefordtimes.com/news/11566002.top-cops-praised-for-serial-killer-snare/ [Accessed 22 January 2024.
Thomas, T. (2023) Lucy Letby sentenced to whole-life jail term after murdering seven babies. The Guardian [online] 21 August 2023. Available from: https://www.theguardian.com/uk-news/live/2023/aug/21/lucy-letby-sentencing-hearing-life-sentence-updates [Accessed 22 January 2023].
Editorial Team
Paul Williamson (Editor-in-Chief); Claudia McCready (Lecturer); Eve Smietanko (Joint Programme Leader & Senior Lecturer); Ian Lowe (Senior Lecturer) & Micah Hassell (Senior Lecturer).

If you would like to contribute as a guest blogger, please contact Police.Blog@uwe.ac.uk

















