As the ITV drama series based on the murders of Trevor Buchanan and Lesley Howell begins tonight, a friend recalls the "genuine and sincere" police officer that he knew.
Kevin McAuley, now a freelance photographer, first met Trevor in 1986 as the police officer and his wife, Hazel, were transferred from Omagh to Coleraine.
"At that time I was a finance officer in the civil service dealing with expenditure in the Police Authority. Trevor came to me to find out about his relocation payments ahead of his move to Coleraine the following week."
At the time Trevor was aged 25, a few years older than Kevin, who had joined the civil service after leaving school.
"My first impression - which was later proven to be true - was that Trevor was a sincere, down-to-earth guy. He would never try to pull the wool over your eyes."
The pair struck up a friendship which was to last until Trevor was killed in May 1991. The bodies of the police officer and Lesley Howell were found in a fume-filled garage in Castlerock. A police investigation concluded that the pair had committed suicide, distraught at the illicit affair between Trevor's wife Hazel and Lesley's husband Colin.
That was the official verdict until 2009, when Howell confessed that he had killed the pair and that Hazel - now known as Hazel Stewart - was complicit in the murders. Howell is serving a 21-year jail sentence for the crime and Stewart 18 years.
Kevin, who is based in Ballycastle in north Antrim, says that when he was originally told that Trevor had committed suicide he was shocked and felt that it could not be true.
"When it later came out that Howell had killed the pair I was not surprised," he adds.
"Trevor had very strong Christian convictions and I never thought that he would have gone down that road, as he would have seen it as wrong in the eyes of God."
He adds: "As a policeman he attended other cases of suicide and I can remember talking to him about them. I recall him saying that he wondered how people could take their own lives and what would drive them to do it.
"When I was told that Trevor had taken his own life, I felt there was something that didn't add up. That was not the action of the man I knew.
"At that time it was even suggested that Trevor and Lesley had taken their own lives because they were having an affair and had been found out. That certainly never rang true."
But although Trevor - like Lesley, Colin and Hazel - was a member of Coleraine Baptist Church, he was never overtly religious.
Kevin says: "He didn't go around preaching or pushing religious views down people's throats."
At that time, in the mid-1980s, police officers used to socialise mainly in their own recreation clubs and Kevin and Trevor met there frequently. "He didn't drink and neither did I. He was a quiet man whose main interests in life were his job, his church and his family. I never met Hazel and, of course, never learned about her affair with Howell until it became public knowledge."
Tellingly, he adds: "Perhaps Trevor was not exciting enough for his wife," - a comment she is said to have made to their church pastor when he confronted her about the affair with Howell.
"Obviously their two children - son Andrew and daughter Lisa - were very young at the time when I was in the civil service, so that meant a lot of his focus was on his home life."
Kevin and Trevor maintained their friendship after Kevin left the civil service to become a photographer. "My impression was that Trevor did not have any hobbies, certainly none that he talked about to me. But he was very interested in photography, as I was, and we used to chat about it.
"He later became a scenes of crime officer and I would meet him regularly in the following years - sometimes two or three times a week.
"I would be covering incidents for newspapers and he would be there in his professional capacity."
During all their meetings there was never any indication from Trevor that anything was wrong with his marriage. "In his day-to-day conduct there was nothing that suggested he was unhappy or dealing with any issues or problems."
Kevin describes Trevor as "not being a typical policeman. He was the sort of person who would have given people a chance to correct their wrongdoing. He didn't go out to give people a hard time. If he knew they did some minor wrong, he would tell them not to do it again.
"That was the sort of thing that a village policeman would have done in some quiet backwater, but it was refreshing to see it happen in Coleraine. It could have been difficult for him to take that attitude.
"Essentially he was a policeman because he wanted to help people, not because he wanted to pursue them."
Speaking after viewing the first episode of The Secret on UTV Player, Kevin admits that some people may feel that it is being screened too soon after all the details of the murders became public knowledge. But we have to realise that a lot of dramas are based on true events, just as this is. We live in a very small community in Northern Ireland and it is easy for people to connect to this case. It would be different if these events had happened in London or Birmingham or some other major city.
"There are many people who knew the victims and the killers - leaving aside even their families - and they may be upset that this drama is being screened.
"However, people have to live in the real world and accept that a television series has been made. I don't have any issue with this drama, but others may have a different opinion."
Going by the first episode, he feels that the drama is faithful to the actual events leading up to the deaths.
"The Baptist Church features heavily and some people might think that this is an attack on the church," he says.
"However, churches are made up of real people, some of whom may have affairs or commit what the church regards as other sins. The church in this instance cannot run away from its role in the events.
"People might argue that churches are very good at covering things up but, in this case, those involved were all prominent members of a particular church. They met there. That is properly portrayed in the drama. It shows that the pastor of the church tried to put things right and was convinced for a while that the affair was over.
"Since the details of the case became public, some people have been critical of the church for not doing more, but, as anyone knows, affairs are very difficult issues to meddle in, even for churchmen."
He also found the portrayal of Trevor good. "It makes it clear that he was a victim along with Lesley Howell. At one stage Trevor asks the pastor if his wife's affair with Howell was his fault. That seems like Trevor, wondering if it was due to some failing on his part, rather than on the part of others".
His final verdict on his friend: "You could not have met a more civil chap than Trevor Buchanan. He was the sort of guy you could talk to about anything. He was very good at giving people advice".
Coleraine Baptist Church, which features heavily in the opening episode, was asked for its views on the drama. It declined, but Associate Pastor Richard Blayney issued the following statement on behalf of current members of the church: "As a church fellowship we would like to express again our sincere Christian sympathy to all those who have been bereaved. We were deeply shocked and appalled at what was recently established as the truth of what happened 25 years ago. We continue to pray for God's grace in the lives of those affected by this terrible tragedy."