A man accused of murdering a woman whose body was discovered bound and gagged in a Buckinghamshire lake more than three decades ago admitted raping a 14-year-old girl six years earlier, a court has heard.

Donald Robertson, who was was also convicted of raping a 17-year-girl less than two months after Shani Warren was found, is accused of murdering Shani Warren 35 years ago.

The 26-year-old woman's body was found in Taplow Lake, Buckinghamshire, in April 1987.

Robertson, who is now aged 66, denies the false imprisonment, indecent assault and murder of Ms Warren between April 16 and 19 that year.

He was charged in October 2021 over her death.

RECAP: What the jury heard on day one of the trial

Robertson also denies the kidnap and rape of a 16-year-old girl, who cannot be identified, on July 16 1981.

That incident is said to have happened less than four miles away from where Ms Warren's body was found.

Opening the trial at Reading Crown Court on Friday, prosecutor John Price QC told the jury Robertson pleaded guilty in October 1981 to the rape of a 14-year-old girl.

The court heard that the rape, which happened in August of that year in Buckinghamshire, saw Robertson threaten the child with a broken bottle and tell her during the attack: "Don't bloody scream 'cos if you do, you'll be scarred.'"

Outlining what he described as "distressing detail" in the ordeals of both teenage girls, as well as the state of Ms Warren's body when it was found, Mr Price said there were similarities in each case.

He said: "The prosecution submits it is relevant evidence because it is known and proven conduct of Mr Robertson's which in several aspects is so like that which is alleged to have been done to Shani Warren and (the 16-year-old) as to assist, when combined with other available evidence, in proving that in both cases, he was the person responsible for what happened to them."

READ MORE: Everything you need to know about the man accused of murdering Shani Warren

Reading Crown Court also heard how Robertson raped a 17-year-old woman just 50 days after Shani Warren's body was discovered.

He offered her £50 for sex when she was walking home from Slough in the early hours of the morning but when she refused he forced her into his car and raped her.

It was only in 2010 that Robertson was convicted of rape after police reopened the case.

Jurors were informed of a third conviction from April 1990 when Robertson tried to rape a woman at a B&B in Slough after threatening her with his keys.

Fortunately, she escaped and Robertson was convicted of burglary with intent to commit rape and kidnap in December 1990.

Mr Price described how Ms Warren's body was found on Easter Saturday in 1987 by a woman walking her dog.

The witness, who is now deceased, told police at the time that the first thing she saw was a pair of hands "with beautifully manicured nails", tied with something red, later confirmed to be a car jump lead.

Mr Price said the dog walker had flagged down passing motorists and while one car drove to Maidenhead Police station to report the discovery, the others helped pull Ms Warren's body from the water.

The barrister told the jury they were right to do so as it was not clear at that point whether the victim was alive or dead.

Mr Price told the court: "After the body was taken out of the water, it could now be seen, not only was it bound hand and foot, but also gagged by a piece of cloth wrapped around the head and knotted towards the back, at the left side."

He said the police investigation which followed established she had most likely died at some point on the evening of the day before, which was Good Friday.

The jury was told that a post-mortem examination gave the cause of death as drowning, with Mr Price saying: "In other words, she must still have been alive."

He said that aside from the restraints to her wrists and ankles and the gag over her mouth, "there was discovered fresh bruising to her neck" which he said suggested the forceful application of a ligature of some kind.

As well as this, "fresh, pin-prick sized haemorrhages or bleeds" were seen on the skin of her face, eyes, and scalp, which he said are known as petechiae.

He said the findings "put together, pointed strongly to an act of strangulation occurring before she died".

The court heard that Robertson was questioned by police in 1981, six years before Ms Warren's death, about the rape of the 16-year-old girl. He denied the offence at the time and was released.

The alleged victim of that assault will give evidence during the current trial, the jury was told.

At the beginning of proceedings on Friday, the jury was told that the dock in court was empty because the defendant had chosen not to attend the trial.

Mr Justice Wall said it is Robertson's own choice not to attend, that he has a right to make such a choice and that it should not be held against him.

The trial continues.