Just before Christmas 1992 14-year-old Johanna Young went missing from her home town of Watton in Norfolk. She was described by her parents as full of fun and always up to tricks.
Now on the anniversary of Johanna's disappearance, her mum and dad have urged anyone who knows what happened to come forward.
Despite a major police investigation, her killer has never been tracked down.
Johanna Young was last seen alive on 23 December 1992. Three days later on Boxing Day, her partially clothed body was found lying in a pond. She'd suffered a fractured skull.
Her parents, Carol and Robert rarely speak publicly about their ordeal, but on the anniversary of Joanna going missing, they agreed to be interviewed in the hope they will find out what happened to her.
– Carol Young
"Somebody around here knows, somebody knows who it was. Why can't they come forward and tell.
Carol Young said: "When it happened we had two other children and you had to try and make things normal as possible for, and now we have grandchildren as well . They never knew Johanna, so to them Christmas is just Christmas, so you have to try and be as normal as possible but we still think about her."
The last known sightings of Johanna were in Watton town centre on December 23rd She was seen near a fish and chip shop at 7.30pm.
– Detective Inspector MARIE JAMES, Norfolk & Suffolk Police Major Investigation Team
"It was a very cold foggy night. She saw friends and people she knew in the town but was last seen at 8.45pm on 23rd December. After that we don't know where she went or who she was with until she was found, sadly, on 26th and she was robbed of her life."
- Click below to watch a report by ITV News Anglia's Malcolm Robertson