A woman who was kidnapped and raped aged 16 by serial predator Donald Robertson has said she can “finally get some closure” following his conviction decades after the ordeal.

The victim, who cannot be identified, called Robertson “the monster that put my life in turmoil” as she thanked her family and officers for helping her pursue the case to justice as an adult.

Robertson attacked her before he went on to murder 26-year-old Shani Warren in April 1987.

He was charged last year with Ms Warren’s murder after a police cold case team found new DNA evidence linking him to her death.

Ms Warren, who lived in Stoke Poges in Buckinghamshire, was found in Taplow Lake on the Easter weekend in 1987.

Robertson, 66, did not attend his trial and the dock at Reading Crown Court was empty on Tuesday as a jury found him guilty of both crimes.

He was convicted of the false imprisonment, indecent assault and murder of Ms Warren between April 16 and 19 – her wrists having been tied with a car jump lead and ankles bound by a tow rope.

Donald Robertson court case
Shani Warren, whose body was found in a Buckinghamshire lake more than three decades ago (Thames Valley Police/PA)

Speaking in a statement issued through Thames Valley Police, the other victim said: “It’s been almost a year since the investigation was reopened, and to relive that dreadful night has been very distressing.

“The weeks leading up to the trial have been very traumatic for myself and my family, but with their support I found the courage and strength that I didn’t have as a 16-year-old to pursue the case against the monster that put my life in turmoil.”

The victim added: “Justice has been done and I can finally get some closure. So to anyone that finds themselves in a similar situation, don’t be afraid to ask for help, be strong and with your courage and the right support you will get through the trauma.”

The brother of Shani Warren also paid tribute to his “warm” and “caring” sister as he described how her loss left a “gaping hole” in the family.

In a statement through Thames Valley Police, Stephen Warren said Ms Warren’s parents had died last year with her murder “never resolved in their minds” as he said no sentence would be harsh enough for the “psychopath” and “coward” who killed her.

“From the day Shani was born, our family dynamic changed. Not just with the usual baby things, and the subsequent arrival of dolls, dresses and so on, but over time, our new little addition grew into a wonderfully pretty and happy child whom everyone immediately took to their hearts,” he said.

“On Good Friday, 1987, after mowing the lawn, another duty she resolutely took on, she ‘popped out’ to dispose of the grass cuttings, get some food, and buy a card and Easter egg for an ex-boyfriend. She was due back, likely in an hour or so.

“But it is one of life’s tragedies that everything can be destroyed in an instant. Somehow or other, Shani encountered the serial rapist Donald Robertson, whose practice was to attack unaccompanied young girls and women, terrifying them into submission with vicious threats and abuse.

“We cannot imagine what the last moments of Shani’s life must have been like, but you may agree that no punishment is enough for her attacker; a psychopath and a coward who lacked the courage to attend court, or even to give evidence via a live link.”

He added that his sister’s death has left a “gaping hole in the family” and she was a “a force of energy, hope and positivity”.

“Her parents never recovered, and for us all, nothing felt the same again,” he said.