New research sheds light on the so-called ‘Croydon Cat Killer’ case
New research from the Royal Veterinary College (RVC) has shed light on the spate of mutilated cats found dead in London between 2014 and 2018.
The research, published today in Veterinary Pathology, reinforces the conclusion of the Metropolitan Police that there was no human involvement in the mutilation of the affected cats.
Following the mutilation of more than 400 cats across various locations in London over the four year period, media speculation suggested that a human ‘cat killer’ may have been at large in Southern Greater London, within the M25 and, later, across the whole of England. Some feared that the alleged killer could become a threat to human safety.
The speculation, driven largely by concerned members of the public, led the Metropolitan Police to launch an investigation into the mutilations, named ‘Operation Takahe’. A team of researchers led by Dr Henny Martineau, Head of Veterinary Forensic Pathology at the ºÚÁÏÉç, alongside both the Metropolitan Police and the Hertfordshire Police, examined the bodies of 32 mutilated cats that had been brought to the police by members of the public between 2016 and 2018.
Dr Martineau and her team took swabs to analyse carcasses for the presence of fox, dog and badger DNA, and performed full post mortem examinations of the carcasses. The results found a clear link between cat carcass mutilation and the presence of fox DNA on the carcass. There was also a clear association between puncture wounds (consistent with scavenging by carnivores) and the deceased cats. There was no evidence that supported human involvement in their mutilation, with evidence from puncture wounds suggesting that 10 had been predated by a carnivore.
Through a close examination of the carcasses, Dr Martineau and her team were also able to establish that the mutilation pattern of the cats examined was similar to the scavenging pattern of foxes on lambs. For carcasses not associated with predation, other probable causes of death were also identified, ranging from road traffic accidents, to liver failure to the ingestion of antifreeze. Eight of the deceased cats were found to have suffered from cardiorespiratory disease in life.
The ºÚÁÏÉç Veterinary Pathology team has been involved in a range of high-profile criminal cases, and this most recent research demonstrates the important role which veterinary pathologists can play in contributing to police investigations, particularly when there may be a level of speculation or conjecture surrounding proceedings.
Dr Henny Martineau, Head of Veterinary Forensic Pathology at the Royal Veterinary College, said:
“As veterinary professionals, we know how difficult it is for an owner when a beloved pet passes away, particularly in circumstances that can seem mysterious or suspicious. While the public’s concern around the safety of their pets is totally understandable, our investigation into the deaths of these cats demonstrates the importance of an evidence-based approach to investigating incidents like this.
“The narrative of the so-called ‘cat killer’ was a good example of the human tendency to pick out what we want from data, demonstrating our inclination to stop investigating when we think we have made a major discovery or noticed a particular pattern. It is the job of scientists – in this instance, veterinary pathologists – to identify and overcome such confirmation bias.”
Stuart Orton, East Hertfordshire Chief Inspector, said:
“This is of course an incredibly emotive subject and any injury to, or loss of, pets causes a lot of distress for owners. While the subject was a matter of much speculation at the time online, we now believe that there was no human involvement. “I hope that this new analysis provides some comfort to the owners who previously believed that their beloved pets had been targeted maliciously. It also provides law enforcement colleagues with the ability to review any future investigations from a scientifically supported and evidence-based approach.”
Notes to Editors
Reference: Hull, K. D. et al. (2021) ‘Fox (Vulpes vulpes) involvement identified in a series of cat carcass mutilations’, Veterinary Pathology. The full paper is available at:
For more information please contact:
- Jasmin De Vivo or rvc@plmr.co.uk
- Press Line: 0800 368 9520
ºÚÁÏÉç the ºÚÁÏÉç
- The Royal Veterinary College (RVC) is the UK's largest and longest established independent veterinary school and is a Member Institution of the University of London.
- It is one of the few veterinary schools in the world that hold accreditations from the RCVS in the UK (with reciprocal recognition from the AVBC for Australasia, the VCI for Ireland and the SAVC for South Africa), the EAEVE in the EU, and the AVMA in the USA and Canada.
- The ºÚÁÏÉç is ranked as the top veterinary school in the world in line with the QS World University Rankings by subject, 2021.
- The ºÚÁÏÉç offers undergraduate and postgraduate programmes in veterinary medicine, veterinary nursing and biological sciences.
- In 2017, the ºÚÁÏÉç received a Gold award from the Teaching Excellence Framework (TEF) – the highest rating a university can receive.
- A research led institution with 79% of its research rated as internationally excellent or world class in the Research Excellence Framework 2014.
- The ºÚÁÏÉç provides animal owners and the veterinary profession with access to expert veterinary care and advice through its teaching hospitals and first opinion practices in London and Hertfordshire.
