Blood on the Altar: In Search of a Serial Killer, By Tobias Jones

On 12 September 1993, Elisa Claps went to meet a friend at church in a backwater province of southern Italy, and vanished without a trace. She was 16, from a loving family, and her suspected murder captured the attentions of first the Italian, and then the international, press and public.

Her disappearance from the sleepy town of Potenza is the foundation on which Tobias Jones's true-crime story is based. The book begins as she leaves home and ends, 18 years later, when her mummified cadaver is found in the upper vaults of Potenza's church.

This trajectory has its fair share of macabre and unbelievable twists before it reaches it conclusion. If it were fiction, we'd think it fanciful – Danilo Restivo, the suspected murderer, is an oddball who snips off women's hair on buses; his father is the well-connected director of the National Library's local branch who plays "spin the bottle" with young couples; the husband of the magistrate dealing with Elisa's disappearance has connections with the mafia. But the biggest twist - a ritualistic murder and mutilation of a British mother, Heather Barnett, nearly ten years later in Bournemouth, where Restivo comes to live - is one that Jones could never have anticipated when he began his investigations.

The book begins with an air of reflective erudition. Jones gives us somewhat loquacious topographies and cultural histories of the Basilicata region and draws parallels between the inner workings of the investigation - the obfuscation and bungling by police, magistrate and church - with the murky workings of the state itself. He follows the trail of half-truths and conspiracies right up to the top of the pyramid of duplicity upon which Berlusconi's Italy is built. He befriends the Claps family and acquaints himself with the investigation's cast of dubious characters (not least, the priest who goes to a thermal spa on the day Elise disappears and locks up the church) as well as its heroes (an honest priest; a good-looking detective; the tenacious older brother, Gildo, and the indomitable mother, Filomena).

The connection he makes between one unsolved mystery and the state is supported by his keen knowledge of Italy. Jones drew a similar parallel in his travel book, The Dark Heart of Italy, in which he asked: "Why is it that there are so many mysteries in Italy? Why is it that no journalist or historian or judge can ever say what's been going on?" Similar questions are asked here. Yet it is not Jones' "top down" corruption theory that makes this book so riveting but the human dramas: Gildo, with his steely will and quiet sense of tragedy, Filomena, a devout Catholic who is betrayed by the institution to which she has been so faithful, and the creepy Restivo, with his provincially powerful family.

Jones has a detective's eye for faces and physical tics; he gives us a blow-by-blow account of Barnett's court case, with a meticulous understanding of its forensic evidence. And he captures, most poignantly, the Claps family's trauma, heroism and drive to see justice done. As Filomena says: "You have to be brave every day."