The body of 14-year-old Caroline Glachan was discovered in West Dunbartonshire in August 1996.
Three people have been arrested in connection with the death of schoolgirl Caroline Glachan more than 25 years ago.
The body of the 14-year-old was discovered on the banks of the River Leven, near Place of Bonhill in Renton, West Dunbartonshire, on 25 August 1996.
Police said two men, aged 42 and 43, and a 42-year-old woman had been charged in connection with the death.
All three are due to appear before Dumbarton Sheriff Court later.
Det Ch Insp Stuart Grainger, of the major investigations team, said: “I would like to thank the members of the public who have assisted with our investigation and those who have come forward with important information surrounding Caroline’s death.”
Caroline, from Bonhill, was a pupil at Our Lady and St Patrick’s High School in Dumbarton at the time of her death.
Her friend Joanne Menzies was one of the last people to see Caroline at shops near her home at 23:54 on 24 August.
She was last seen at about 00:15 when she walked down Dillichip Loan towards Dillichip Bridge, known locally as the Black Bridge – which no longer exists – and then on to the river tow path.
The teenager’s body was discovered later that day on what was her mother Margaret McKeich’s 40th birthday.
Caroline’s death went on to feature on the BBC’s Crimewatch programme and became one of Scotland’s most high-profile unsolved cases.