Crimewatch will screen a special feature tonight on the Claire Tiltman murder investigation.

The 16-year-old Dartford Grammar School student was stabbed in an alley off London Road, close to her home in Greenhithe in 1993.

Claire's friends fought for justice for more than two decades before her killer Colin Ash-Smith was jailed for life in December, after being found guilty of her murder.

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The case ended one of Kent's largest ever investigations.

The BBC programme will include a new reconstruction and interviews with Claire's friends and detectives involved in the case.

Claire was viciously attacked just four days after her birthday and as she walked to a friend's house. But her killer evaded capture because forensic evidence was unavailable.

Watch: Claire's friends speak out

Lawyers acting on Ash-Smith's behalf confirmed they will appeal the conviction.

He was jailed for life and will spend a minimum term of 21 years behind bars before becoming eligible for parole.

The application will then go before a judge and, if permission is granted, a hearing will be heard at a later date at the Court of Appeal in London.

Crimewatch is due to air tonight at 9pm on BBC1