Peter Manuel was Scotland’s first convicted serial killer, hanged in 1958 for the brutal murders of teenager Isabelle Cooke, three members of the Watt family, and three of the Smart family. He was a lifelong criminal who committed his first rape when he was twelve years old. Manuel’s horrifying crimes are well documented but Denise Mina’s haunting The Long Drop has taken a different approach, using the Manuel case to tell the story of a city in transition.

The war was 15 years earlier but parts of Glasgow are still as poor and unsanitary as they had been a century earlier. The city is split along several fault lines: religion, finance, law, class, architecture. Social order is maintained through an unofficial understanding between Glasgow’s police force and it’s most powerful crime lords. It’s a practical arrangement and everyone knows their place within it. Times are changing though. The city is ripe for redevelopment and there is money to be made.

Everyone is seeking respectability. Gangsters use money or fear to become ‘respectable’ businessmen. Peter Manuel is small fry but craves respect. He’s a petty criminal who has progressed from reform school to borstal to prison. Although highly intelligent, he has no empathy. By modern definition he is a psychopath. Other criminals seemed to sense this and, although well known, he is not well liked.

The Manuel case was famous in its day and Denise Mina clearly had plenty of contemporary accounts to help her analysis of Manuel’s character. But the author’s real achievement is to so convincingly evoke the Glasgow underbelly that Manuel inhabits. It’s a male-dominated world of woodbines and whisky, wet raincoats and steaming cups of tea.

Manuel’s intelligence has no creative outlet other than storytelling. He uses this skill to win the trust of his victims and accomplices. He kills men, women and children without motive or emotion. He confesses to impress and retracts to annoy. He’s a fantasist unable to see that his lies do not convince. In court he fires his lawyers and represents himself. Calling himself to the stand, he gives an extraordinary six-hour monologue that effectively guarantees his conviction.

The Long Drop is marketed as a novel, and it is certainly as compelling as Mina’s other work but I wonder about this categorisation: the array of outlandish personalities and circumstances often tests credulity yet these people did exist and these events did happen. While I can admit to enjoying a crime novel I hesitate to admit ‘enjoying’ the true story of a serial killer. Mina’s style is lean, dispassionate and insightful. The horror and, yes, the humour, of Manuel’s world is convincingly conveyed without becoming exploitative.

Even as the case came to court vast areas of the old city were being swept aside to make room for lucrative new developments. Within six years, ground would be broken for the Red Road Flats. As Manuel awaits his execution at Barlinnie he listens to pop music on Radio Luxembourg. Times are changing fast and Glasgow no longer has room for a man like Peter Manuel.

The Long Drop, by Denise Mina is published by Harvill Secker, and out today.