DNA evidence has given detectives hope of solving the case
Detectives trying to solve the murder of a teenager from Bath 25 years ago are to make a national TV appeal for information.
Melanie Road, 17, was sexually assaulted and stabbed to death as she made her way home from a city nightclub in the early hours of 9 June 1984.
Her killer has never been caught but a cold case team believe a single tip-off could be enough to find the offender.
Police will appeal for information on the BBC One Crimewatch programme later.
Her brother Adrian Road has also taken part. He said: "Over the last 25 years it's been a living nightmare to know someone out there killed my sister. This person took Melanie from me."
Avon and Somerset Police's Major Crime Review Team is responsible for investigating unsolved murders.
Officers believe they have the killer's DNA from the crime scene. The profile does not match anybody on the national database.
Melanie left friends to walk home after a night out at the old Beau Nash nightclub in Kingston Road, Bath.
Her body was found yards from her house at St Stephen's Court at 0530 BST by a milkman and his 10-year-old son.
More than 90 arrests were made in connection with the murder, but no-one has ever been charged.
Det Ch Insp Mike Carter said: "If there was someone acting suspiciously, at that time, we can check them against our DNA sample."