Shani Warren murder: Family speak of pain as Donald Robertson jailed

Shani Warren pictured with her father. Both her parents died last year and "never recovered" from her murder, her brother Stephen said

A family has said their 35-year wait for a murderer to be brought to justice was "full of pain and sorrow".

Shani Warren, 26, was found bound and gagged in Taplow Lake, Buckinghamshire, in April 1987.

New DNA evidence linked her death to 66-year-old serial rapist Donald Robertson, who was jailed on Thursday.

In a statement issued by police, Ms Warren's family said they hoped to find "a little peace" after he was sentenced to a minimum of 30 years.

Robertson, who did not attend his trial at Reading Crown Court, was convicted of the false imprisonment, indecent assault and murder of Ms Warren and given the mandatory life sentence.

The family statement said: "As we have said before, the trial has been a difficult experience to deal with, so we now need to be left alone to process what has happened."

'Outrageous' suicide theory

Robertson was also found guilty of the kidnap and rape of a 16-year-old girl in Slough in Berkshire in 1981.

Police were able to charge Robertson after a cold case investigation uncovered new DNA evidence.

The court heard Ms Warren, of Stoke Poges, was assaulted, strangled and thrown into the lake, which is between Maidenhead and Slough.

The investigation was initially plagued with problems, with an "outrageous" initial conclusion from a pathologist that Ms Warren may have committed suicide, the family said.

Donald Robertson is already in prison, having been convicted in 2010 of another attack, on a 17-year-old girl

In 1981, Robertson had been questioned and released by police over the kidnap and rape of the 16-year-old girl in Slough when, just days later, he raped a 14-year-old girl in nearby Farnham Royal.

He pleaded guilty to the rape of the 14-year-old at the time.

In 1987, less than two months after Ms Warren's murder, and only a few miles from Taplow Lake, he raped a 17-year-old girl who was walking home having missed her last train.

He was behind bars for that crime during his trial, having been convicted of it in 2010, after that case was also reviewed by police.

The family statement added that the repeated reopening of the investigation over the intervening years was "a tribute to the resolve of the police to never give up", and the crucial DNA analysis was "not possible" in 1987.

"The evidence could easily have been lost or disposed of, but it was stored to provide a solid base for future work," it added.

'Evil sex offender'

Peter Beirne, head of Thames Valley Police's cold case team, said: "Donald Robertson is an evil sex offender and murderer who preys upon women and girls.

"Robertson has spent the majority of his adult life in jail for a series of offences, including kidnap and rape.

"During his life, no sooner has he been released from incarceration, he has committed another heinous crime on an innocent victim.

"Society is much safer with Robertson behind bars."