A woman has been arrested over the murder of a Co Londonderry teenager close to his home over 20 years ago.
Jonathan Cairns, from Ballykelly was attacked as he made his way home from a night out with friends in the early hours of Sunday, April 25 1999.
The 18-year-old's body was found stripped and bound in a shallow grave in the remote Loughermore Forest, not far from his parents' house, later that day.
His bloodstained clothes were also discovered in the grounds of Glasvey Special School.
The victim's body was found by his cousin, a police officer who was taking part in the search operation, 15 hours after he was last seen alive.
Detectives investigating the cold case arrested a 44-year-old woman in the Dungiven area yesterday.
She was taken to Musgrave Serious Crime Suite in Belfast for questioning.
A 49-year-old man was previously jailed in 2002 for perverting the course of justice in relation to Jonathan's murder.
Philip McGroarty, from Ballykelly, was given a five-year sentence for helping to dispose of Jonathan's body after being found guilty following a nine-day trial at Londonderry Crown Court.
Despite a huge police manhunt and a £30,000 reward, no one was ever charged over the killing.
Police say the investigation is still open and have renewed their call for information about the case.
Speaking after yesterday's arrest, Detective Inspector Adrian Brown said Mr Cairns' family deserve answers.
"I continue to appeal for information in relation to Jonathan's murder," he said.
"For over 20 years, Jonathan's family and friends have suffered intolerable grief and they deserve answers.
"I understand their desire to see justice done and I believe that people within the Ballykelly community have information that could assist my investigation.
"Some people were not prepared to come forward at the time for a variety of reasons but I am asking people to search their conscience and think again.
"Circumstances and loyalties may have changed over years and it is never too late to do the right thing.
"Anyone with information should call detectives on 101.
"Or, if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111."
Yesterday's arrest comes almost seven months after the Cairns family made an emotional appeal for information on the 20th anniversary of Jonathan's death.
At the time his father Raymond appealed for anyone with information to come forward.
"Jonathan was 18 when he died, he should now be 38 - maybe with kids of his own. We think about him every day. He was always smiling, always happy," Mr Cairns said.
"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."
Four years ago Raymond and his wife Hazel set up a Facebook page called Justice for Jonathan Cairns, which has attracted more than 5,000 likes, in a bid to help unlock the silence from those who know who murdered their son.
The investigation into Jonathan's murder has so far involved the identification of more than 2,500 witnesses, with statements taken from 872 people and in excess of 20 searches.