At around 2am on 1 January 1958, in merry mood during Hogmanay celebrations, the serial killer Peter Manuel, then 30, took the telephone from his sister Theresa and sang Al Martino’s “Here in My Heart” down the line to her friend Mary, a nurse on duty at Glasgow’s Southern General hospital. Approximately three hours later, Manuel took a short walk to a bungalow in Uddingston, seven miles outside Glasgow, where he murdered the Smart family – father, mother, 10‑year-old son – in their beds, shooting each in the head. Over the following few days he made repeated visits to the scene, making himself at home among the bodies, and making sure to open a tin of salmon for the cat.

It is notable that the crime writer Denise Mina, in her semi-fictionalised account of the Manuel case, avoids such tempting “novelistic” details. She leaves out the song and doesn’t make much of the cat. Hers is a tighter focus. Manuel, “the Beast of Birkenshaw”, murdered eight people in Lanarkshire between 1956 and 1958, and is therefore a ripe subject for drama – hence the recent ITV series In Plain Sight. But Mina is interested, in particular, in his relationship with William Watt; Watt (rightly) suspected Manuel of killing his wife, daughter and sister-in-law, a triple homicide of which the bereaved man himself had, for a time, been under suspicion. Watt, therefore, had every reason to hate him and wish to see him hang. Instead, they went drinking.

The Long Drop takes its title from a method of hanging. It also has the ring of a bar name; Mina’s narrative alternates between Manuel’s murder trial and that strange 11-hour pub crawl on which he and Watt embarked in December 1957. The book is a radical reworking of her 2013 play Driving Manuel. In that theatrical treatment, Watt was presented as an innocent. In The Long Drop, based in part on court transcripts, Mina explores a theory – touched on by Manuel during the trial – that Watt was complicit in the deaths of his own family. To say more would be a spoiler, but one wonders about the ethics of such speculation. Those alleged to be involved are no longer alive to defend themselves.

Mina’s detective fiction has won many awards. This is her first novel-length foray into true crime, a genre especially popular in her home town, where it sometimes seems that no bookshop is complete without its shelf of gangsters, sutured and booted, looming from covers. Glasgow, as she writes, is “a city that reveres angry men”, but Manuel, a psychopath who badly wanted to be seen as a hard man, has never attracted reverence; the subject of appalled fascination, he is still loathed in Scotland.

Peter Manuel, c1950. Photograph: Popperfoto/Getty Images

Mina only rarely tells this story from his point of view. She seems more at ease in summoning the Glasgow of the period, “a memory of a memory of a place”, all fag smoke and black stone and wet streets in which even the gang graffiti – “Come On, Die Young” – has a certain fatalism. This “shadow city” she peoples with real figures from the time, including the razor thug Billy Fullerton and crime boss Dandy McKay, relishing the creative act of putting flesh on their unlovely bones. The best three chapters in the book are told from the perspective of minor characters: the father of the teenager Isabelle Cooke, strangled with her own bra; Manuel’s mother, Bridget; and Watt’s sister-in-law, Nettie, cowering away from the killer in an outside toilet. Curious that the inner life of Manuel himself does not receive such close imaginative recreation. Perhaps Mina considers him unknowable, or is unwilling to think herself into the murk of his head.

Manuel wrote his name in blood across postwar Scotland. Mina’s attempt to trace that signature in ink is interesting but perhaps ultimately unnecessary. It was, in any case, indelible.

• The Long Drop by Denise Mina (Harvill Secker, £12.99). To order a copy for £9.74, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.