Former Thames Valley officer Brian Langston has continued to utilise his detective skills after leaving to investigate the past.
The fact that a police officer doesn't hand in their curiosity along with their warrant card at the end of service is proved by the extra-curricular activities of Brian Langston (pictured).
He's made the transition from the ACPO team at Thames Valley, cooling racial tension after 9/11 as the area commander of Windsor and Eton, to investigating crimes of times gone from his house in France.
Having already published one book of his findings, True ghosts and ghouls from Windsor and Eton, a collection of stories gathered over the 25 years he spent policing the area. He's also got another book in the pipeline which he hopes to be out for Hallowe'en.
He told PoliceOracle.com: "It's more about stories that have been lost for hundreds of years or more and just bringing them back and refreshing them and how the evidence stacks up."
Swapping a dimly lit interview room for historical records and archives, he pieces together instances of crimes and miscarriages of justice, some of which reveal a shockingly primitive approach compared to today's standards.
In his book he recalls a story from the 18th century where a pub owner from Exeter had gone missing. His drinking partner from the night before was charged with his murder after he was unable to offer an explanation as to where he'd gone.
While the suspect was being held in custody, one of the town's residents was visited by the ghost of the dead pub owner who confirmed that the suspect was guilty of his murder and the suspect was hung. Thousands gathered to watch him swing from the gallows where he protested his innocence to the end.
Three years later, the pub owner's wife sold the premises unable to live there after her husband's death. Which is when the new owners made a gruesome discovery, the body of the man underneath some floorboards in the toilet, lying in the cess pit beneath with no signs of foul play.
"He was found with his trousers around his ankles," Brian explains, "He had clearly gone for a pee in the middle of the night and fell into the cess pit and drowned in a vat of crap. The guy they hanged hadn't done a thing."
Brian also recalls another horror story involving notorious East End gangster Ronnie Kray and Peter Sutcliffe, an encounter he tells from a memory during his time in CID in the 80's.
The pair, who were housed in the "old scary Victorian part" of Broadmoor Hospital, had to be interviewed as part of an investigation into an escaped inmate whose cell was on their landing. But Brian landed into difficulty as he hadn't made an appointment with Mr Kray.
His cell was guarded by a "7 foot tall ginger Irish bloke" and Brian returned having made an appointment and was greeted by Ronnie's "formidable presence" as he helped them with the enquiry before his patience ran out.
"He had every possible convenience in his cell and was wearing an immaculate very sharp suit, he was very well turned out," said Brian, "It was clear he was still running his empire from inside."
Mr Kray, notorious for his ambivalence towards the police terminated the interview abruptly. "He ended up saying 'I've had enough now sergeant, now fuck off', so I did," Brian added.
Peter Sutcliffe aka The Yorkshire Ripper, didn't command the presence of his co-habitant. "He was a pathetic individual, despised by everyone in there," Brian said.
Among his stand out successes in his career he recounts an incident where his team had to arrest a Muslim groom on his wedding day, as part of a sensitive counter-terrorism operation, creating a situation that had the potential to cause unrest.
"In some other parts of the country that would have caused a riot but because of the trust we had built up we managed to do it," he said,
"You can imagine the amount of tension that it could cause and we managed to do it without any problems at all."
"The high levels of community support for the police was one of the things that I hoped would live on after I had left," he added.
The Wolverhampton-born Brian was newly married and on the dole, living in area he'd later go on to call a "priority neighbourhood" when he joined Thames Valley after he was rejected by his native West Midlands.
"If you'd got a pulse you were in. I wasn't even sure where Thames Valley was to be honest," he said.
Admitting that he never intended to reach ACPO level, he did have a great deal of ambition which saw him complete a law degree and an MBA (Masters of Business Administration) while he was a serving officer. Though eventually shelving his plan to leave the police and become a solicitor.
As he approached retirement, Brian had planned to retreat with his wife to their house in the Southern France and write the book he had been threatening to write for years. But he decided to capitalise on his leadership skills that were hard won during his ascent to assistant chief constable.
But his post-retirement project, The Phenomenal Leadership Company, a company set up to share leadership skills that were hard-won on the job, began to take over.
Regularly phoning his wife alone in their home in France while he was spending his time in soulless hotels and airport lounges and soon became disillusioned.
"It really really grew very tiresome. I was stuck in a formica hotel in Shanghai while my missus is waiting for me to get back,'" he said, "So I stopped that and thought I'd do stuff that I could do from home.
He's now an antique dealer and spends his time scouring the flea markets of Southern France for new stock. He's even written a guide to navigating them alongside his crime writing.
So given his diverse path of retirement, what advice would he give for officers planning life after their policing careers?
"Don't necessarily do the most obvious thing, go with your passion," he said, "Don't put off till tomorrow what you can do today because you don't know how long you're going to be a member of NARPO for."