He has now investigated more than 330 cases involving more than 750 officers.
His favourite relates to 1979 when three unsuspecting bobbies parked up for a chat and a cigarette in a quiet country lane at 3am."One of the best to come my way was from Chiltern in the Thames Valley in 1979 involving a PC Eric Rayment and two of his colleagues," he said. "It was an amazing report."
They didn't think much of a bright white light in the distance that blurred into view for a few seconds before continuing their conversation."Five minutes later and suddenly the bright white light appears and it's the size of a football pitch shining a beam down the width of a football field," said the father-of-three."It was at an altitude of about 500 feet and was about a mile away from where they were."
After moving its beam across the landscape a remarkable thing happened.
"There are smaller objects flying around the larger object akin to the mother ship and suddenly it's gone, as corny as it sounds," the detective said.