A “killer” who dumped the body of a woman in a lake raped a 16-year-old girl in Slough several years earlier, a court has heard.

Donald Robertson, 66, formerly of Slough, is on trial accused of the murder, unlawful imprisonment and indecent assault of Shani Warren, who was found dead in Taplow Lake in 1987.

Robertson is also on trial at Reading Crown Court accused of raping and kidnapping a 16-year-old girl in Slough in June 1981. The girl cannot be named for legal reasons.

Robertson denies all of the charges against him and has chosen not to attend the trial.

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On Tuesday, Robertson’s alleged victim attended court to give evidence on when she was sexually assaulted at the age of 16, on June 16, 1981.

Before the woman took to the witness stand, prosecution barrister Alan Blake read from a statement she made to police in July 1981.

The court heard how on the day she was attacked, the girl was followed by a “youth” who spied on her through holes in a fence, before assaulting her and knocking her over.

The man, who the victim guessed was about 19 years old, then dragged her through a field near Warrenfield School, which has since been replaced by Becchwood School.

After crossing the field, the victim and her assailant reached the edge of a small woodland, where he proceeded to rape her.

Reading from the victim’s statement, Mr Blake said: “I thought I saw someone looking at me from the playing fields through one of the holes in the fence. A youth dropped down from the fence and ran towards me.

“I screamed and ran to the road. He said ‘don’t scream, I’ve got a knife.

“I said let me go, and he said ‘I’m going to f*** you first’. I said ‘where’s your knife then?’ and he said if I want to kill you I’ll strangle you.”

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The court heard that after the assault took place, the attacker forced his victim to tell him where she lived, and warned her that if she told anyone else he would “get” her.

Reading from the statement, Mr Blake said: “He said, ‘if you say one word to anyone or if I see anything in the papers I’ll get you, and I have got seven brothers and if I don’t get you they will.’”

Despite being fearful of the warning, after she got home the victim and her mother went to the police to report the crime. Not long later, police identified Robertson, who was living on the Britwell Estate at the time, as a suspect.

On July 31, 1981, the victim went to Maidenhead Police Station to view an identity parade, where Robertson and eight other volunteers were shown to the victim, who was still only 16 years old and was not accompanied by a family member or a friend.

The court heard that the victim did not pick Robertson out of the line up while she was in the room. After the parade concluded, she told officers that she thought he was in the room, despite not picking him out.

Taking to the witness stand, the victim told the court why she did not immediately identify Robertson as her assailant.

She said: “I was told by the police officer I had to be 110 per cent sure, and I was scared that I might be wrong.

“I remember I was terrified because they wanted me to be 110 per cent.”

Donald Robertson has denied counts of rape and kidnap in June 1981.

He has also denied the murder, unlawful imprisonment and indecent assault of Shani Warren in 1987.

The trial continues.

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