Musselburgh crime writer and former senior police officer Peter Ritchie on how real life crimes inform his novels

Former Chief Superintendent turned author Peter Ritchie is talking ahead of the launch of Our Little Secrets, the fifth novel in his Detective Grace Macallan series, at Waterstones on Wednesday 10 July.

Over three decades, Peter went from being a humble police constable based at the station on the High Street of his hometown, Musselburgh, to the heady heights of Chief Superintendent.

Along the way he found himself assigned to CID, murder squads, Serious and Regional Crime Squads, NCIS London and Europol.

Peter Ritchie on the beat in Musselburgh in his early days with the Force

Over the years, Peter was regularly pitted against some of the darkest forces of human nature. Two particular cases, however, still return to haunt him, even now.

He explains, “As a police officer, you are supposed to remain detached, you do try, but it doesn’t always work .

“In my case, I worked for a few years specialising in offences against women and children.”

One of those was the investigation into serial killer Robert Black.

“My daughter was exactly the same age as Caroline Hogg at the time she disappeared, so it was hard to be detached. You can’t always avoid the emotion,” he says.

Black was jailed in 1994 for the murders of three girls including 11-year-old Susan Maxwell in 1982 and five-year-old Caroline Hogg, from Portobello, in 1983.

He was later convicted of a fourth killing in 2011.

“The day Caroline went missing, I was actually working on another murder, that of a sex worker who was found down at Gypsy Brae.

“I remember Detective Chief Superintendent Brian Cunningham coming into the room to say it was Caroline.

“We were a pretty tough bunch of hardened guys in the Serious Crime Squad, but there was a real sense of shock.

“It was a hard one and it doesn’t leave you; everyone of us still casts our minds back over old cases and wonders what we could have done differently.”

Peter was also instrumental in the investigation and arrest of Charles Calderwood Hay, a police officer who attacked women over a long period.

“I was always struck by the fact I’d worked with this guy for years. Those are the ones that stick with you; the people who seem ordinary, above board, almost dull... but then they have this ‘other self’.

“Charlie was a dog handler, had a kid in the same class as my son, I knew his wife of old and, as I say, he was a pillar of the community.

“It was a total shock when I realised all these attacks, over all these years, were by one of our own - you would not have spotted Charlie in a crowd.”

Working such extreme cases does change you, admits Peter, who was also a deep sea fisherman from the age of 15, before joining the Force at 23.

“Different guys go different ways. Some can handle it. Some handle it in the pub. Some talk it out.

“You just have to keep reminding yourself that you are doing a job, remain focussed, and keep your emotions under control as best you can.”

Operating in a world of such depravity, it was writing that allowed Peter to keep in touch with his humanity.

“I’ve always written poetry and painted and drawn - that has been really important to me,” he reveals.

“Having seen collegues whose approach to life maybe became a bit too cynical - it’s hard not to when you see what we see - writing has certainly been good for me.”

There’s little doubt Peter’s experiences add to the authenticity of his novels, though perhaps not always consciously.

“I saw quite a lot of trafficked women and sex workers when I worked in London and Holland and that has obviously affected me too,” he says.

“It’s not intentional, but those themes always seem to creep into the books, there’s always a sex-worker... and in the third book, probably the one I enjoyed writing the most because I managed to get fishing boats into it, the boat that brings the women over is called The Brighter Dawn, which was the name of my dad’s boat.”

Our Little Secrets Launch, Waterstones, Princes Street, Wednesday, 6.30pm, free

THE INVESTIGATIONS OF DETECTIVE GRACE MACALLAN

PETER RITCHIE’S fifth novel in his Detective Grace Macallan series of novels, Our Little Secrets, follows on from the highly praised Where No Shadows Fall.

Edinburgh’s gangland is in turmoil. As a new breed of upstarts challenges the old criminal order, their battle for territory causes serious havoc.

Into the war steps DI Janet Hadden. Ambitious, hard-bitten and addicted to risk-taking, she knows how to throw opponents off balance.

But when she’s thwarted, Hadden seeks help from a notorious underworld fixer, a man who always extracts a price.

Beset by violence and double-crossing, Grace is soon embroiled in a savage game of cat and mouse that could take her down unless she holds her nerve.

Previous novels in the series are Cause of Death, Evidence of Death and Shores of Death.

Published by Black & White in paperback, £8.99