A NOISY STREET IN CENTRAL Florence. There are four names on the doorbell but no Michele Giuttari. I’m late so I call his mobile: “It’s the bell with no name. Press that one.”

It makes sense. Giuttari, a successful crime writer, is also a policeman of nearly 30 years’ standing and has made a number of enemies.

Like his fictional hero, Chief Superintendent Ferrara, Giuttari is fifty-something, “well groomed, with a slight Sicilian accent, longish black hair combed back and streaked with white at the sides . . . sideburns white, in contrast with thick black eyebrows which accentuate the shape of his eyes.” Add a German wife and a penchant for good cigars and you have a serious case of fictional alter ego.

“There is no doubt we are close, Ferrara and I,” he says. “Though he probably has a better life than I do. He gets to listen to music, go to the theatre. Me – I’m always working too hard to do anything like that.”

Over the years Giuttari has had a lot on his plate. Born in Sicily, he spent half his working life in Calabria investigating Mafia kidnappings. As part of the AntiMafia Squad, first in Naples and then in Florence, he was in the team that cracked a series of killings and bombings. But in 1995, when he took over the Squadra Mobile (flying squad) in Florence, he confronted a different kind of crime.

“The tourists who come to this city think of it as all art and beauty – palazzos, the Ponte Vecchio, churches, museums – but there is a history of brutality as well as beauty. In the 1970s and 1980s there were terrible crimes, cases of extreme sexual violence, women murdered and mutilated. It was as ferocious and brutal as anything I dealt with in the South.”

That ferocity was nowhere more apparent than in the “Florence Monster”, a series of murders that gripped the city for decades (and inspired Thomas Harris’s sequel to The Silence of the Lambs). From the late 1960s into the 1990s, 16 courting couples were murdered, usually in cars, often with the woman sexually mutilated.

In the early 1990s a man with a history of sexual violence was convicted, but the evidence proved unsound. His conviction was overturned, then reinstated. He died in prison, but, by then, the idea of the lone killer was under suspicion, especially by Giuttari: “At the time the idea of the serial killer was becoming a cliché. But in this case it didn’t fit the facts.”

Giuttari uncovered that the murders were the work of a group. Two more men are now in prison, but with rumours of the occult, satanic rituals and Freemasonry, the whole story may never be known. What is clear is that not everybody wanted Giuttari’s investigations to continue.

“Some very unpleasant things happened to me. My car was tampered with, tyres slashed, brakes cut. In many ways I was fighting the authorities as much as the criminals. The only good thing that came from it was that it turned me into a writer. The writing was a kind of therapy, but it has become my great pleasure.”

The “therapy” started with a book on the case. Then came A Florentine Death, now translated into English for the first time, introducing Ferrara also head of the Squadra Mobile and known for the Monster investigation.

Here fiction takes over, with a series of what appear to be random killings of gay men. The reader can identify the killer fast enough and the story is not so much who did it as why, and what will happen when the murderer becomes involved with a young woman with her own secrets. At root it’s a rather conventional plot: more interesting is the politics of police work: Ferrara’s spiky relationship with his bosses and the mundane, sometimes frustrating, journey from crime to solution.

“Of course the difference between writing and doing the job is that in fiction there has to be a solution. Each case is like a different piece of theatre. People watch television or see the bits of an investigation that hit the headlines and think it looks glamorous, even dangerous. But the real work is in your head.”

The idea of investigation as theatre is most evident in the interview room, where Ferrara comes alive with a mixture of chess moves and cat-and-mouse games. “There is so much going on. A mix of intellect and intuition. The way someone walks into the room, the way they sit. And timing is important. The moment at which you ask one question and not another. I have a good memory for information. If I read a book or watch a film, it’s gone the next day, But I remember details from cases 30 years ago.”

This affords him a formidable data-base for writing fiction. Regular visitors to Florence could learn a lot about the city: how the Cascine park on the banks of the Arno, with its thriving weekly market, offers a very different kind of commerce after dark; how high-class antiques might have a less than high-class provenance – like the painting Ferrara uncovers in a shop where a victim worked: a 17th-century Velásquez stolen from a church in Sicily.

“Actually, the connection between the Mafia and the Florentine antiques trade is more my imagination than fact,” he says “although the theft of that painting and its return to Sicily is absolutely true. We found the Velásquez in Calabria, just in time – it was due to be smuggled out of the country in a few days. When we took it back to the church, the whole village turned out. It was very moving.”

That’s interesting, because Giuttari doesn’t come across as a man easily moved. Maybe he is used to playing his cards close to his chest. “He has always kept everything to himself,” his wife Krista (as caring and solicitous as her fictional counterpart, Petra) confides at dinner in their favourite restaurant. “Since his hair went grey he’s become a little softer.” She pauses. “But not much.”

Still, he is enjoying his second career (the three Ferarra novels have been translated into nine languages). In the restaurant they keep his books on the front shelf and the chef oversees the meal. Towards the end he disappears. After a while I wonder if he has left. “No, he is paying the bill.”

As he returns I get out my wallet. She takes my hand and pulls it back down. “He is Sicilian, remember.”

A Florentine Death by Michele Giuttari, translated by Howard Curtis

Abacus, £10.99; 352pp

Buy the book here for the offer price of £9.89 (free p&p)

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