The net could be tightening on the evil Croydon Cat Killer after tests confirmed the pets were mutilated by a human, the RSPCA has claimed.

Met Police have stepped up their investigation into the horrific series of slayings, and the number of victims could rise from more than 50, after officers vowed to go back through their archives to look for any copycat killings.
Scientific analysis of several headless cats found dumped across south London shows the victims were hit by a car before being decapitated, according to the charity.
The bodies of more than ten felines have been found butchered in and near Croydon in the past five months – and more than 50 over the past two years.
The deaths have raised fears of a sick serial killer, also known as ‘Jack the Rip-purr’ and prompted a specific police investigation into the deaths, which are all thought to be linked.
Although the RSPCA initially suggested foxes could be behind the deaths, post-mortem investigations conducted by forensic experts show that humans were involved.

A spokesperson said: “Early analysis indicates that the likely cause of death was blunt force trauma, potentially consistent with being hit by a moving vehicle.
“Examination of the bodies we have received showed that the heads and tails appear to have been removed by a human, after death.”
Animal rights campaign group PETA has offered a £5,000 reward for information leading to the arrest of the cat killer.
The lead police investigator involved in the case said despite the RSPCA’s findings, they still can’t rule out accidental death because of the evidence suggesting cats were first hit by a car.
Detective Sergeant Andy Collin said: “It could be deliberate but we can’t say at this stage.
“What we do know is that when the cats are mutilated this is done so after they have died.
“They may be killed and mutilated by the same person or killed and mutilated by someone else.
“We know for certain that the six cats that have been examined have definitely been mutilated after they have died, and we know they have been mutilated by a human hand.”


Police also acknowledged that some members of the public have been expressing concerns that the killer may move on to people – but have said they have no specific intelligence of that kind.
Det Sgt Collin said: “It is difficult, there is a known correlation and link – in the states serial killers have often started with animals – although it doesn’t work in the other way.”
“But if someone has mutilated an animal it doesn’t necessarily follow that they are going to progress to people, but it is something that we are aware of.”
Police have been criticised by local pet owners for what they deem a slow reaction to the cases, but now the hunt for the alleged killer is on in full force.
Det Sgt Collin said: “We are revisiting all the alleged offences going back years and trying to use a bit of graphical profiling and following up calls from the public.
“Someone must know who is doing it or be suspicious of someone.
“We are doing absolutely everything we can to try and catch the individual or individuals concerned and it is being taken very seriously.”


A number of celebrities including Martin Clunes and Dermot O’Leary have backed calls to find the killer.
The RSPCA has appealed for any suspicious deaths to be reported.
A spokeswoman said: “Please be reassured that we take all reports of animal cruelty very seriously.
“A dedicated team is continuing to work closely with the police and looking into all evidence given to us to see if there is deliberate cruelty involved.
“We are particularly keen to be called if and when a cat is found dead in suspicious circumstances so we can do all relevant tests and investigate what killed him or her.
“We would also appeal for any drivers who believe their vehicle could accidentally have hit a cat to contact the police as part of the ongoing investigation.”