"My wife, Maureen, had been arranging for a family reunion in Auckland. Instead, I was going over to Scotland to collect her ashes. It was the longest journey of my life."
Reid was a neighbour of Elaine's and it is thought he gained access to her flat by pretending he needed to use her telephone.
Police believe he struck her on the head with a weapon inside her home before dragging her into her bedroom by the feet.
There, he tied her to the bed, gagged her with a towel and tortured her with live electrical wires to obtain the PIN number for her bank card.
He then subjected Elaine to a brutal and sadistic sexual assault before suffocating her.
Police later recovered pornographic bondage magazines and related equipment from Reid's flat.
Reid pleaded guilty to Elaine's murder and was jailed for 15 years. Collie was unhappy with the sentence, so he and his only child, his UK-based journalist son Jason, launched a personal investigation into the brutal killer's dark past in a bid to keep him behind bars for longer.
Collie has made "seven or eight" return trips to Scotland in the past 12 years to track down and interview previous victims of Reid.
He has also met and corresponded with Scottish MPs, police, psychologists and the press to convince authorities the killer is still a danger and should not be let out in 2014, when he can be considered for parole.
He believes statements from Reid's previous victims show earlier assault convictions were sexually motivated.
They were part of a pattern of escalating violence that was not taken into account when Reid was handed his original 15-year jail term, he says.
Collie hasn't totted up how much money his globe-trotting crusade has cost him but it runs into tens of thousands of dollars.
"My wife has never once grumbled about the cash and has backed me all the way," he explains.
"We needed to get proper justice for Elaine and as we are a family with enough financial and other resources to conduct our own investigation, it was something that I just had to do.
"When I started getting the grim details about Elaine's death I simply shut down for a while because I just couldn't take it all in.
"But I snapped out of it and became determined to do whatever it took to prove Reid is still a real danger to the public."
Collie moved to New Zealand with his parents, Alfred and Kathleen, when he was 18 months old. Elaine was just a baby at the time.
Originally from Northern Ireland, the family moved back there when the kids were teenagers.
While in Northern Ireland, Elaine had worked for a Minister in the now defunct Parliament. When her parents died she moved to Glasgow where she had relatives.
But she had long been fascinated with the colourful history of Scotland's capital city of Edinburgh and ended up there in the late 1970s where she was employed at a firm of solicitors.
Collie preferred to stay in Auckland, where he started his own business.
He only saw Elaine a handful of times between then and her death.
"In the 1970s and 80s it wasn't as easy to get to Britain as it is now and I didn't have the money for all that travel," the grandfather-of-two says.
"I last saw Elaine at Jason's wedding in England a year before she died and the whole family got on very well with her. We loved her.
"She never married and kept herself to herself, but she was also very bright. She was the type who would turn the other cheek and for Reid to take advantage of her in the way he did still sickens me to the core."
Collie made a harrowing solo journey to Northern Ireland to bury his sister's ashes beside their deceased parents.
He vowed then he would do whatever it took to make sure her killer never got the opportunity to put another family through a similar ordeal.
Many years on, he is still campaigning. "This is not a crusade aimed at keeping Reid in prison until the day he dies," he insists.
"It is about us trying to ensure the people who make the decisions about him getting parole have the full picture about the true nature of his past offending."
He adds: "Reid is only in his mid-50s and I wouldn't like to see someone like him out before his 70th birthday.
"I don't care how many more trips back to Scotland it might take. We will see this through to the end."