A fresh appeal for information about the murder of Jonathan Cairns has been made by his parents and police on the 20th anniversary of his death.
Mr Cairns was 18 when he was attacked in Ballykelly, County Londonderry, on his way home from a night out on 25 April 1999.
His body was found in a shallow grave in Loughermore Forest the next day.
A man was jailed for helping to dispose of his body but no-one has ever been convicted of his murder.
Speaking alongside Mr Cairns' mother Hazel, his father Raymond said it was never too late for someone to come forward to help the police with their investigation into the murder.
He said: "It's been 20 years, 20 years since our son was murdered, 20 years of living each day without our lovely son, 20 years of living without answers, and without justice.
"He should now be 38 - maybe with kids of his own. We think about him every day. He was always smiling, always happy.
"The people who did this took our son away from us and we don't know why. All of his family loved him and miss him so much. Please tell us what you know."
The investigation into Mr Cairns' murder has involved more than 2,500 witnesses, statements from almost 900 people and 20 searches.
Detectives will be conducting more searches in the area as part of the appeal.
A mobile police station has been opened in Ballykelly village for anyone who wishes to speak with police.
Det Insp Adrian Brown said: "I believe Jonathan's killer or killers were local to the area and they may have known Jonathan.
"I also believe that people within the Ballykelly community have information which could help solve this case."
"Jonathan's family and friends have suffered intolerable grief. Their son died a violent death as a result of a vicious beating and we understand their desire to see justice done.
"We are committed to doing all in our power to apprehend those involved in this brutal incident, which went far beyond a drunken assault."
Det Insp Brown appealed for anyone with information about two men who were seen on the Loughermore Road in the early hours of 25 April 1999 to contact officers.
He said: "They were in their early 20s, about 5ft 10in tall and one of them might have had auburn coloured hair.
"They have never come forward to speak to police despite numerous appeals which leads me to believe they were involved in the murder."