Police have launched a fresh appeal for information on the murder of a schoolgirl 40 years ago.
Lisa Hession, 14, had been walking back from a party when she was sexually assaulted and strangled in an alleyway 200 yards from her home on Bonnywell Road in Leigh, Greater Manchester Police said.
Her body was found behind Rugby Road by a member of the public at about 11.55pm on December 8, 1984.
Lisas mother, Christine, had expected her home by 10.30pm and reported her missing at 10.45pm, according to the force.
On the anniversary of her death, GMP said: Despite our efforts and obtaining a DNA sample, which could lead us to a detection and the conviction of Lisas killer, we have never found a match, and no-one has ever been charged with Lisas murder.
Sadly, Lisas mum, Christine, passed away in 2016 without the knowledge of who killed her daughter.
The force has re-appealed for members of the public to come forward if they saw anything unusual that night or have information that could assist the investigation.
No matter how small or insignificant you think it may be, it could be a vital piece of the puzzle that could help us solve this four-decade-long case and finally get some closure for Lisas family and friends, and a community that still mourns her loss, it said.
Police have launched a fresh appeal for information about the murder of 14-year-old Lisa Hession
Lisa was sexually assaulted and strangled on the night of December 8, 1984
A £50,000 reward for information leading to the identification and conviction of Lisas killer is still available.
Lisas killing shocked a close-knit community and many believe her attacker was local.
She was a popular pupil at Bedford High School and a tree was planted in her memory in its grounds.
In the three months before Lisas murder, three young women were attacked in the same area of Leigh by a sex pest - including one the night before Lisa died.
Detectives believe the attacks could have been committed by Lisas killer.
The three previous victims gave consistently described their attacker as having a local accent, aged 18 to 20, and each time threatening to kill.
The head of GMPs Cold Case Unit, Martin Bottomley, said: In what is the 40th anniversary of Lisas death, we want to let her loved ones, friends and the community know that we are committed to not losing hope on getting answers.
This case has been subject to a number of reviews since 1984. The reviews have concentrated on using advances in forensic techniques and investigating all information provided to GMP by members of the public
An article dated January 16 1985 reporting on the release of a picture of a baby-faced man of 20 with whom police wanted to speak at the time
Pictured: The alleyway where Lisa was assaulted, just 200 yards from her home in Leigh, Greater Manchester
Lisa, a young teenager, who was a keen gymnast and ran cross-country for Leigh Harriers, had her whole life ahead of her, and somebody took that away from her.
Her mother, Christine, never got to see her daughter grow up, and she died never knowing who killed Lisa.
Sadly, the case still remains undetected but will always be open until Lisas killer is brought to justice, and any information received will be followed up appropriately.
Anyone with information is asked to contact the GMP Cold Case Unit on 0161 856 5978, or speak anonymously to Crimestoppers on 0800 555 111.