A “troubled” young man has been convicted of fatally stabbing his grandfather in the neck.

Ben Oliver was on trial over the death of 74-year-old David Oliver in Mottingham, south London, on January 19 last year.

The 25-year-old defendant had denied murder but admitted manslaughter.

It was said on his behalf that he had Autistic Spectrum Disorder, which combined with other emotional and mental factors, diminished his responsibility for the killing.

An Old Bailey jury deliberated for a couple of hours on Monday to acquit Ben Oliver, of Bexleyheath, south London, of murder.

Previously, Louis Mably QC had told how bedbound David Oliver was attacked as he lay “helpless” in his bedroom.

He said: “He had been repeatedly stabbed and slashed with a knife in the face, and in particular in the neck, which had effectively been cut open.

“It was a brutal attack, plainly carried out with the intention of killing him.”

The prosecutor said the defendant had become “very angry” after learning of allegations against his grandfather of historic sexual abuse of girls.

On the morning of January 19 last year, without warning, he took a kitchen knife, went into the bedroom and killed David Oliver, the jury was told.

Mr Mably said Ben Oliver had told his grandmother what he had done immediately afterwards.

He said the issue for the jury was the defendant’s mental state at the time.

Mr Mably told jurors that the defendant grew up in “troubled and difficult times”.

In 2016, Ben Oliver was convicted of sexual offences against a young girl when he was aged 15, the court was told.

He was released from youth detention in September 2019.

In the months before the killing, he became aware of allegations of sexual abuse against his grandfather, who was also said to have treated his wife badly and had affairs.

The defendant was also depressed and had suicidal thoughts, jurors were told.

Mr Mably said: “He was a troubled and angry young man.”

Judge Sarah Munro QC adjourned sentencing until June 27 and remanded the defendant into custody.

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