Jonathan, who was just 18 and from Ballykelly, was attacked as he made his way home from a night out in the early hours of Sunday, April 25, 1999.
His body was found in a shallow grave in Loughermore Forest, not far from his home, later that day.
His bloodstained clothes were also discovered in the grounds of Glasvey Special School.
A 49-year-old man was jailed five years for perverting the course of justice but no one has been convicted of Jonathan’s murder.
Detectives will be conducting searches in the area today, Thursday 25th April and police officers will be handing out leaflets.
A mobile police station will also be open today until 7pm in Ballykelly village at the junction between Plantation Road and the Main Street for anyone who wishes to speak with Police.
Jonathan’s father Raymond is appealing for anyone with information about their son’s murder to come forward to police.
Raymond said: “Today I am making this appeal as it’s been 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.
“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.
“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.
To anyone who has information, it’s never too late to come forward. Please tell us what you know.”
The investigation into Jonathan’s murder has involved:
• The identification of more than 2,500 witnesses
• Taking statements from 872 people
• In excess of 20 searches
Leading the investigation, Detective Inspector Adrian Brown said: “For 20 years, 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.
“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.
“I appreciate that this happened a long time ago but I would appeal to people to think back to the Saturday night and Sunday morning of 24th-25th April 1999.
“If you were in the Clooney Road/Loughermore Road/Caman Park areas of Ballykelly between 1.30am and 9am on Sunday 25 April and haven’t spoken to us, please speak to us.
“Two men were seen in the area where Jonathan was assaulted on the Loughermore Road in the early hours of Sunday 25 April 1999.
“They have never come forward to speak to police despite numerous appeals which leads me to believe they were involved in the murder.
“They were in their early 20s, about five foot 10 inches tall and one of them might have had auburn coloured hair.
“Some people were not prepared to come forward at the time for a variety of reasons but we are 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.”
The mobile police station will be open today, Thursday 25 April from 10am to 7pm.
It’s located beside the pub formerly known as the ‘Droppin Well’ (2 Plantation Road, Limavady, BT49 9HX).
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