'It's all about the truth now, as there will be no justice'
Sergeant Joe Campbell was shot dead as he closed Cushendall police station in February 1977.
The Catholic father-of-eight was killed by loyalists with, his family allege, police collusion.
His son Joe jnr described him as "a community policeman" years before the phrase became common.
"He didn't wear his uniform very often," he added. "He saw himself as a Glensman, as someone who was part of that community. Loyalist RUC men and the Army were bringing in guns (from Canada) to the Antrim coast. Those guns were being stored in halls.
"My father found out and he shared that information with people in the RUC. So my father was murdered because of what he knew.
"The initial investigation didn't go anywhere. My mother went to see the Chief Constable at the time. He brought out a buff folder with three or four sheets of paper.
"My mother's comment to him was that there would have been far more paperwork for a sheep lost on the side of the mountain than there was for my father's murder.
"We're no different from any family in any other part of Northern Ireland. We were brought up to know right and wrong, to respect police, teachers, and priests.
"To then have everything you were brought up to believe in (shattered) was really difficult, because where do you go then to have any grievances resolved? Who do you turn to?
"In truth, back in those early days there was nobody to go to. My father was murdered on February 25, 1977. I left Northern Ireland in September that year. I've been in London since then.
"I decided to go away because I couldn't cope with what had happened. I didn't want to do something that was going to cause further problems for my family.
"In later years, I decided to channel my efforts into establishing the truth. It's really about the truth now. There will be no justice."