Two men who were found guilty of murdering a schoolgirl after evading justice for almost three decades intend to appeal against their convictions and prison sentences.
The pair were jailed for life earlier this month.
O'Brien was ordered to serve a minimum of 22 years before being eligible for parole, and Kelly 18 years.
Donna Marie Brand, 44, who was also found guilty of murder, was unfit to attend court and will be sentenced in March.
Both O'Brien and Kelly now intend to launch a bid for freedom.
On Monday, a spokesperson for the Scottish Courts and Tribunals Service said: "We have received intimation of intention to appeal for both O'Brien and Kelly on their conviction and sentence."
Caroline's body was found in the River Leven in West Dunbartonshire on 25 August 1996 - the day of her mother's 40th birthday.
The killers - who were teenagers at the time of the murder - were eventually caught after Police Scotland reinvestigated the case in 2019.
More than 200 statements were taken from people who had not previously spoken to police and, from that, officers from the Major Investigations Team were able to discredit their alibis.
Judge Lord Braid said: "It is hard to find words to describe the evil nature of your crime, but three which come to mind are brutal, depraved, and above all, wicked."
During the trial last year, the jury heard that Caroline met boyfriend O'Brien, Kelly and Brand at a bridge near a towpath beside the river, between Renton and Bonhill.
There, the trio shouted and swore at her and repeatedly punched and kicked her on the head and body.
The court also heard they threw bricks or "similar instruments", 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.
A forensic pathologist told the court Caroline's ultimate cause of death was drowning.
Lord Braid said O'Brien was the main perpetrator and used "extreme violence" on the teenager.
The judge said while Kelly played a lesser role, he was also involved in inflicting "murderous violence".
He added that the trio's actions deprived Caroline's family of seeing the woman that she would have become.
Caroline's mother, Margaret McKeich, spoke outside court following O'Brien and Kelly's sentencing and said she was "over the moon" that justice had been served for her daughter.