Up to 500 cat killings were not the work of a serial killer, but foxes, police have decided.

Following a thorough examination of the available evidence, Met Police officers working alongside experts have concluded that hundreds of reported cat mutilations in Croydon and elsewhere were not carried out by a human and are likely to be the result of predation or scavenging by wildlife.

The incidents also include those in Leigh, Billericay and Wickford.

In November 2015, officers began an investigation into reports from members of the public of mutilated cats, often found with their heads and tails removed, in Croydon and the surrounding area.

Officers worked closely with the RSPCA and local charity South Norwood Animal Rescue League (SNARL) from the outset.

There was no evidence that any of the cats had been killed by a human, however media reports of a ‘Croydon Cat Killer’ or an ‘M25 Cat Killer’ led to widespread public concern about cats being harmed and subsequently many more allegations were received.

In 2016, SNARL arranged 25 post-mortem examinations on cats that had been found mutilated. These were conducted by a veterinary pathologist. The cause of death was found to be blunt force trauma, such as collisions with vehicles. The mutilations were found to have occurred after death, and some of these were thought to have been caused by a sharp implement.

On the basis of these examinations, six cases of cat mutilation were deemed suspicious and the Met’s duty to investigate was established due to the corroborative information in terms of allegations from SNARL and initial veterinary pathology results.

While investigating these six cases, officers in Croydon collated over 400 additional reports made to the Met by members of the public or animal charities of cat mutilations across London and surrounding counties. They were recorded to provide an overview and to prevent colleagues across the Met and in other forces from spending many hours responding to individual reports and allegations.

The investigation took almost three years, due to the number of reports and allegations received from the public and the need to work with specialists to scrutinise any evidence.

No evidence of human involvement was found in any of the reported cases. There were no witnesses, no identifiable patterns and no forensic leads that pointed to human involvement. Witness statements were taken, but no suspect was identified.

In three instances where CCTV was obtained, footage showed foxes carrying bodies or body-parts of cats.

Officers also took note of expert opinion - including a recent, widely reported New Scientist article - which highlights how wildlife is known to scavenge on road-kill, often removing the heads and tails of dead animals.

Similar cases were investigated by Hertfordshire Constabulary. Dr Henny Martineau, the Head of Veterinary Forensic Pathology at the Royal Veterinary College, carried out post-mortem examinations on three cats and two rabbits in June 2018. She concluded that the mutilations had been caused by predation and/or scavenging, and highlighted that fox DNA had been found around the wound sites on all five bodies.

Taken together, this left the conclusions from the six post-mortem examinations deemed suspicious as the only evidence that any cat had been mutilated by a human.

The veterinary pathologist who carried out the original post-mortems conducted re-examinations on the six bodies in August 2018. He found puncture wounds not found previously on some of the animals and concluded that some had been potentially scavenged.

Additional forensic tests were carried out, and these did not show any clear difference between marks on the bodies of cats that had been scavenged and the cats whose mutilations had been deemed suspicious.

Such apparent spates of cat mutilations are not unknown in the UK and elsewhere. Officers were aware of a spate of reported mutilations some 20 years ago which were eventually attributed to predation by wildlife. However the evidence initially provided by the six post-mortem examinations warranted further investigation of the more recent spate.

On Thursday, 20 September, Croydon officers met with SNARL and the RSPCA to set out the investigation’s final conclusion that there is no evidence of human involvement. All of the cases of cat mutilation will be recorded as ‘no crime’.

Frontline Policing Commander Amanda Pearson said: “On average, the Met receives over 1,000 calls each month relating to animals and animal welfare.

“We understand the reason for this - people trust the police to help them when they suspect others have done wrong, fear for their own safety or simply are facing situations that they are unable to handle themselves.

“We will always assist the public in an emergency, but I would urge people to report concerns relating to animal welfare in the first instance to the RSPCA.

“The decision was made to allocate a large number of similar reports of mutilated cats to the officers who were investigating the initial spate of such allegations. In particular, they were following up the six suspicious cases identified by the post-mortem examinations.

“While this increased the workload of those officers, it significantly reduced the resources that would have been required for different officers in different units to record and assess each allegation separately.

“It is this collating of reports that enabled officers to work with experts and reach the conclusion that no further police investigations are required into any of the allegations relating to mutilated cats.”