A “pure evil” child killer has been jailed for life with a minimum term of 15 years for the murder of vulnerable six-year-old Rikki Neave in 1994.

James Watson was 13 when he lured the schoolboy to woods near his home in Peterborough and strangled him to fulfil a “morbid fantasy” he had told his mother about three days earlier.

He stripped Rikki and posed his naked body in a star shape for sexual gratification, deliberately “exhibiting” him near a children’s woodland den.

His sentence was determined largely by the age he was at the time he struck.

James Watson court case
Rikki Neave was murdered by James Watson in 1994 (Cambridgeshire Police/PA)

The judge, Mrs Justice McGowan, said: “Rikki was a child too willing to trust and engage with strangers.

“He never had the chance to be happy and lead a normal and fulfilling life. That opportunity was denied to him by his murderer.”

She said his childhood “had been a sad one”, that he was neglected, was “the victim of violent and cruel behaviour”, and only went to school at lunchtimes so he could eat a proper meal.

Watson showed no emotion as he was sentenced.

The judge said he will only be released after serving the minimum term of 15 years – less the more than two years spent in custody – and once the Parole Board is satisfied that he no longer presents a risk to the public.

Rikki’s murder was among the most high-profile cold cases on police files until Watson’s DNA was identified on the victim’s clothes following a re-examination of the case two decades later.

Mother-of-four Ruth Neave was cleared of her son’s murder in 1996 but was jailed for seven years after admitting child cruelty – a conviction she is reported to be considering challenging, many years after her release.

She did not attend court for the sentencing hearing.

She described Watson as “pure evil, with no conscience”, while police said he was “a fantasist, a compulsive liar” who had shown no remorse.

In a witness statement, read on her behalf, Ms Neave said: “Like stones dropping in a pond, it (the murder) has rippled out far and wide.

“Rikki’s murder left a massive hole in our lives and in our hearts

“I miss him so much that it feels like I have had my heart ripped out.”

James Watson court case
James Watson, now 41, was found guilty in April of murdering Rikki Neave in 1994 (CPS/PA)

Rebecca Maria Harvey, Rikki’s eldest sister, broke down as she addressed the court.

She said: “Although I was the eldest, it wasn’t like that as he would look after me.

“Losing Rikki was like losing the other half of me.”

Addressing Watson, but not using his name, she said: “After all these years of living your life you finally get your comeuppance, and Rikki Lee Harvey finally gets justice.”

Watson, now 41, was found guilty of murder in April by a jury which deliberated for 36 hours and 31 minutes to reach a majority verdict after an 11-week trial.

Rikki’s body was found on November 29 1994, the day after he went missing.

Watson had obsessed over newspaper coverage of the killing, copying front page stories at school.

The following month he was interviewed as a witness by police after an elderly resident reported seeing him with Rikki on the nearby Welland Estate.

His lying account was unchallenged, as police wrongly focused on a theory that Ms Neave killed her son and used a buggy to dump his body.

Prosecutors initially felt there was still insufficient evidence to prosecute, but reversed their decision after Ms Neave and Rikki’s sisters called for a victims’ right to review.

Key evidence included Rikki’s last meal, of Weetabix, which fixed his time of death at about noon.

It meant Rikki was killed shortly after being seen with Watson heading to the woods where he used to play.

Rikki’s muddy Clarks shoes also indicated that his walk into the woods was a one-way trip.

James Watson court case
The copse in Peterborough, Cambridgeshire, where the body of six-year-old Rikki Neave was found in November 1994 (Alan Water/PA)

Watson’s sexual interest in younger boys was known to police, who interviewed him over an allegation that he molested a five-year-old in 1993.

An ex-girlfriend later said he had strangled her during sex in woods and killed a bird and spread out its wings, in a sinister reconstruction of Rikki’s murder.

The judge said there was no evidence of sexual activity with Rikki’s body, although Watson had “a sexual interest in little boys”.

In a police interview in 2016, Watson attempted to explain the presence of his DNA on Rikki’s clothes by claiming he picked him up to look at diggers through a hole in a fence.

Watson, who has a long criminal record for convictions including stealing cars, fled to Portugal while on bail on suspicion of murder, but was extradited back to Britain.

Sketch of Mrs Justice McGowan
Mrs Justice McGowan sentencing James Watson (Elizabeth Cook/PA)

Former assistant chief constable Paul Fullwood, who led the cold case investigation, said mistakes had been made and that police initially “charged the wrong person” in prosecuting Rikki’s mother.

But he denied that police missed an opportunity to charge Watson at the time.

He said: “It has taken a significant period of time to get to this point, but we made a promise we would find the person responsible for Rikki’s death, and it’s a promise we have kept.

“Rikki was a six-year-old little boy – he was a kind and cheeky chap, who was cruelly taken under the most horrendous of circumstances.”

Police said there is no evidence that Watson was involved in any other serious unsolved crimes in the area.