Three people who murdered a teenage girl 27 years ago are due to be sentenced.

Robert O’Brien, 45, Andrew Kelly and Donna Marie Brand, both 44, were last month found guilty of killing O’Brien’s 14-year-old girlfriend Caroline Glachan in August 1996 following a trial at the High Court in Glasgow.

During the 10 days of evidence, the jury heard O’Brien, Kelly and Brand had arranged to meet Miss Glachan at a bridge near the towpath beside the River Leven, between Renton and Bonhill in West Dunbartonshire, on August 25 of that year.

The trio repeatedly punched and kicked Miss Glachan and threw bricks or other similar items at her, causing blunt force trauma to her head and body.

She was pushed or fell into undergrowth and her body was later discovered in the river at Place of Bonhill, Renton, on August 25 – the day of her mother’s 40th birthday.

Robert O'Brien, Andrew Kelly and Donna Marie Brand
Robert O’Brien, left, Andrew Kelly and Donna Marie Brand will be sentenced for murdering Caroline Glachan in 1996 (Police Scotland/PA)

The trio will be sentenced at the High Court in Glasgow on Monday.

During the trial, the court heard from Miss Glachan’s mother Margaret McKeich, who said her daughter was “infatuated” with O’Brien but that she did not approve of the relationship as he was a few years older than her.

Mrs McKeich said her daughter had previously disclosed O’Brien had “lifted his hands to her”.

Later in the trial, Miss Glachan’s childhood friend Joanne Menzies, 42, told the court O’Brien had threatened to kill Miss Glachan for “kissing another boy”, and that she had seen O’Brien bully the schoolgirl on more than one occasion.

Margaret McKeich
Caroline Glachan’s mother Margaret McKeich said the convictions marked a ‘great day’ (Andrew Milligan/PA)

Dr Marjorie Turner, a forensic pathologist, told the court the 14-year-old was still alive when she went into the water and the ultimate cause of death was drowning.

The court heard prosecutor Alex Prentice KC argued that evidence given by a boy named Archie Wilson, who was four-and-a-half years old at the time of the murder, during the two-week trial was “pivotal” to the case.

Speaking outside the court after the trio were found guilty, Mrs McKeich said it was a “great day” to see her daughter’s killers convicted.

“This is a day we never thought would happen,” she said.

“It will not bring her back, but at least we know who was responsible is serving time because for the last 25 years, they’ve had their Christmases and birthdays, but my Caroline has been in the ground.”