The family of murder victim Shani Warren have thanked police for their resolve to “never give up” seeking justice after an “evil” serial rapist was jailed for the crime decades later.
Donald Robertson, 66, will likely die behind bars after being sentenced to life with a minimum term of 30 years imprisonment at Reading Crown Court on Thursday.
He was charged following a cold case investigation which found new DNA evidence linking him to the death of 26-year-old Ms Warren, from Stoke Poges, Buckinghamshire, in April 1987.
At a trial which Robertson did not attend, the court heard Ms Warren was assaulted, strangled and thrown into Taplow Lake, where her body was found bound and gagged on the Easter weekend that year.
On Thursday, her family described their wait for justice as a time “full of pain and sorrow,” but during which they had found “tremendous comfort” in the dedication of scientists and officers who fought to crack the case.
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.
But they said Thursday marked a turning point from which they hoped to “find a little peace on our way forward,” praising the work of investigators in ultimately securing the conviction.
In a statement issued through Thames Valley Police, they said: “We note that there have been comments about the case taking so long to solve, but we would like to turn that around.
“The repeated reopening and investigation of this case is a tribute to the resolve of the police to never give up. In 1987, it simply wasn’t possible to perform analysis in the way it happens nowadays, and the distraction of an outrageous suicide theory forwarded by the original pathologist really didn’t help anyone.
“The evidence could easily been lost or disposed of, but it was stored to provide a solid base for future work.”
Robertson was also found guilty of raping and kidnapping a teenager in July 1981.
Just days after being released by police in connection with that offence, Robertson raped a 14-year-old girl who had been riding her bicycle in Farnham Royal, a crime to which he pleaded guilty in October 1981.
And less than two months after attacking and killing Ms Warren and only a few miles from Taplow Lake, he raped a 17-year-old girl who was walking home having missed the last train.
He was behind bars for that crime during his trial, having been convicted in 2010 after the incident was reviewed by police.
Robertson was convicted on Tuesday of the false imprisonment, indecent assault and murder of Ms Warren between April 16 and 19 1987, and the kidnap and rape of the 16-year-old in 1981.
The jury took just seven hours and 18 minutes to reach their verdicts on the five charges.
He did not attend his sentencing at Reading Crown Court after being absent from the dock for the entire trial, during which jurors heard traumatic details of his crimes.
Mr Justice Wall said he would read his sentencing remarks to the defendant despite his absence from the dock.
On the rape of the 16-year-old, the judge said: “You have blighted much of that lady’s life for a few moments of selfish pleasure.”
On Ms Warren’s murder, Mr Wall said he had “no doubt” that Robertson had effectively “sexually assaulted” her at some point during the ordeal.
Mr Wall said the attack would have been “highly traumatic” for Ms Warren, who was fearful of catching AIDS.
“You have shown no remorse for your behaviour,” the judge said.
“You did not even have the courage to attend this trial and confront the evidence of what you had done.
“You are a self-centred man who cares nothing for the suffering and feelings of others and lacks any understanding of the way in which your conduct has destroyed and damaged other people’s lives.”
The 30-year sentence gives Robertson “little hope of ever being able to apply for release” and he will only be released in 2052 if the parole board regards it “appropriate to do so,” the judge said.
“Otherwise, you will spend the rest of your life in prison, however long you may live for.”
Following the sentencing hearing, head of Thames Valley’s major crime review team and senior investigating officer on the case, Peter Beirne 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. Therefore, society is much safer with Robertson behind bars.”