Police are continuing to offer a £50,000 reward to identify the killer who sexually assaulted and strangled a girl as she walked back from a party 40 years ago.
The body of 14-year-old Lisa Hession was discovered in an alley just 200 yards (183m) away from her home before midnight on 8 December 1984 in Leigh, Greater Manchester.
Her mother Christine, who died in 2016, had reported Lisa missing at about 22:45 GMT when she had not returned home at her expected time of 22:30 GMT.
Martin Bottomley, head of the cold case unit at Greater Manchester Police, said: "Her mother Christine never got to see her daughter grow up and she died never knowing who killed Lisa."