Graham Gooch was detective superintendent at Lancashire Police at the time of the murders, and led the inquiry.
Mr Gooch, now a Lancashire county councillor, can recall the time well.
He said: “It was a shocking murder. Tony Marrocco was a hardworking man running his business and he had taken Paul Sandham under his wing.
“And then one day they just didn’t come home from work.
“The police were called and on arrival at the garage they found mayhem inside. Everything had been knocked over and there was the body of Tony and no sign of Paul. From that moment we started to think they had perhaps had a huge falling out and Paul had killed Tony and disappeared.
“The next morning we got the news that Paul had been found in a field and that obviously upped the ante.”
Together with detectives in London, Mr Gooch and his team of 40 officers from across the county were able to eventually track down and capture Terry Clifton.
Mr Gooch said: “In total it took maybe two or three months to get him.
“The trial was most peculiar because he refused to enter from the cells below.
“The judge insisted he was brought up for his sentencing and it took nine officers to get him into court. He was lean and tall and muscular, a horrible man who showed absolutely no remorse.
“He was an absolutely evil man, there’s no two ways about it. He wasn’t stupid, he was just plain nasty.”
The complexity of the case showed how well detectives across the country could work together.
Mr Gooch, who worked for the Metropolitan Police for 20 years before Lancashire Police, said: “Everything came together well and we were very pleased at the time with the result and how the teams worked together. It certainly ranks among the more complicated cases in Lancashire.”