A JURY has been told there is "overwhelming" evidence that a man pushed a stranger from a pier leading to her death.

Prosecutor Alex Prentice QC made the claim as he made his closing speech at the trial of Jacob Foster at the High Court in Glasgow today.

The 29-year-old is accused of murdering Charmaine O'Donnell, 25, at Helensburgh Pier in Argyll and Bute on April 23 last year.

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Foster denies the charge and has lodged a special defence of diminished responsibility.

The trial has heard how Glasgow woman Charmaine had been on a day to Helensburgh with her friend Caitlin McTaggart.

She ended up in the water and died due to severe neck injuries and drowning.

Jurors have been told Foster accepts that he "caused" Charmaine to leave the pier and fall into the sea.

However, he denies this involved any form of assault.

It is instead said that due to his learning difficulties he failed to understand a remark Charmaine allegedly made about being "pushed" into the water.

Mr Prentice said: "I will invite you to conclude that there was an assault.

"I suggest there is overwhelming and unchallenged evidence that Jacob Foster pushed Charmaine O'Donnell off the pier.

"This set in train events that lead to her death."

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The advocate depute added Charmaine "did not expect or encourage" going into the water.

The trial heard how Foster told a police officer at the scene: "I just pushed her. It was just a bit of fun'.

But, Mr Prentice stated: "It was deliberate conduct. It being a joke is irrelevant and not a defence.

"He was acting deliberately and intended to interfere on Charmaine O'Donnell's person."

Mr Prentice asked jurors to view the incident as murderous, but that it was accepted Foster met the "test" for diminished responsibility.

He said, as a result, he was inviting the jury to return a verdict of culpable homicide under diminished responsibility.

Foster's lawyer, however, told the court he should be completely acquitted.

Sean Templeton, defending, said: "It was a young man with learning difficulties who got it wrong.

"At worst, he failed to understand. What happened that day is a tragedy.

"What I ask you do is not compound that tragedy by committing another tragedy.

"What happened was the most unfortunate set of circumstances coming together that lead to this event."

In his direction to jurors, judge Lord Fairley said a conviction of murder was now "not open" for jurors to return.

The jury will continue its deliberations today.