The family of a man beaten to death outside a nightclub in Portstewart a year ago have appealed for people with fresh information about the attack to come forward.
Trevor Spiers died of brain injuries in December 2009 after he intervened to help his friend.
One man has been charged with his murder, and three others with affray.
His uncle Fergal Devlin said the family need to see justice done to enable them to move on.
"Obviously it will never bring Trevor back and that's something his family and friends will have to deal with in their own way.
"If there is some kind of justice for Trevor that would help us achieve a certain amount of closure."
Detective Chief Inspector Ian Harrison, who is leading the investigation, said he knows more information is out there.
"Many people have spoken to police about what they saw that night, and I want to thank them for doing so.
"While one man has been charged with Trevor's murder, I know there are others who saw exactly what happened on 13 December last year.
"There were large crowds both inside and outside the bar before and during the attack, as well as people visiting othe premises in the area at that time.
"We need to speak to them as witnesses.
"The information they have is important to this case, and could help bring justice for Trevor and his family."