The “evil” killer of a three-year-old girl who was snatched from a Yarmouth caravan, sexually abused and drowned will not be released until he has served at least 30 years, a judge confirmed today.

The “evil” killer of a three-year-old girl who was snatched from a Yarmouth caravan, sexually abused and drowned will not be released until he has served at least 30 years, a judge confirmed today.

Mr Justice Field dismissed claims by Gary Hopkins, now known as Xavier Themis, that he was suffering from Asperger syndrome at the time of the brutal murder of Leoni Keating.

The abduction and killing in September 1985 shocked the nation at a time when people were still reeling from the murders of Susan Maxwell and Caroline Hogg.

In June 1986, nine months after the Norfolk killing, drifter and known sex offender Hopkins was given a life term for the child's murder - with a minimum 25-year term before he could apply for parole.

Following a recommendation from the lord chief justice that Hopkins should die in jail, the home secretary increased the minimum tariff to 30 years.

Hopkins has since changed his name to Xavier Themis, and today had his bid rejected for a reduction to the 30-year minimum term. The High Court judge said the “sheer evil” of the crime justified the lengthy term.

The ruling means Themis will not be eligible for parole until early 2016, taking into account the few months he served while awaiting trial.

It does not mean he will automatically be released after he has served 30 years. He could still be refused parole if the Parole Board feels it is unsafe to free him.

Describing the case, the judge said: “During the night of September 13 1985, Themis took Leoni from the caravan where she had been left by her mother.”

He said Themis committed a serious sexual assault, and added: “He then tied her hands behind her back and threw it into the water channel at Barton Mills. Three days later, she was found dead in the water 200 yards away.”

Themis, who was 27 at the time of the murder, is now 50. He will be at least 57 before he is released.

The judge said: “The applicant raises the argument that at the time of the murder he may have been suffering from Asperger syndrome. But even if he were, this would not mitigate the sheer evil and cruelty of the murder.

“The applicant was fit to plead and did not fall within either of the rules governing pleas of insanity. Further, there is nothing to suggest that Asperger syndrome would have given the applicant a defence based on diminished responsibility.”

He added: “The applicant also prays in aid the progress he has made in prison. After a poor start he has done well educationally.

“He has a high IQ. However, in my judgment, his conduct in prison has not been sufficiently exceptional to justify a reduction in what would otherwise be the appropriate minimum term.”