Trapped in his own thriller

Douglas Preston, the best-selling thriller writer, left his home in coastal Maine to vacation in Italy with his family in February. Two weeks into the trip, Preston was summonsed to appear before Judge Giuliano Mignini in Perugia. He was given an official warning for perjury, false testimony, and withholding evidence. ''The judge verbally accused me of planting evidence, and of being an accessory to murder after the fact, which scared the hell out of me," he says by phone.

The charges are related to a nonfiction book Preston has co-written about a serial killer known as the Monster of Florence, who murdered and mutilated 14 people in the hills of Florence from 1974 to 1985. The case is one of the longest, most expensive criminal investigations in Italian history. In ''Dolci Colline di Sangue" (''Sweet Bloody Hills"), which will be published in Italy next month, Preston and his Italian coauthor, crime journalist Mario Spezi, criticize Mignini for the way he is running the Monster of Florence investigation. According to Preston, Mignini believes the killings were the work of a Satanic sect, dating to the Middle Ages, that needed female body parts as offerings to the devil in Black Masses. Preston and Spezi think this theory is hogwash and have said so. Preston says Spezi, who covered the crimes during the '80s, is also being investigated for a murder the police believe is related to the case, as a way to intimidate him.

In 2004 Spezi appeared on Italian television and ridiculed Mignini's investigation. Shortly after, on Nov. 18, police showed up at Spezi's apartment in Florence at 6 in the morning and seized his papers, computer, and the book manuscript. The search warrant, signed by Mignini, stated that Spezi was under investigation for 18 crimes labeled ''A" through ''R," all unspecified and listed as ''segreto" (''secret"). According to Preston, Spezi has never been told what these crimes are.

In response, Preston contacted PEN International, a writers association whose mission includes fighting intimidation of journalists. In January 2005, after an investigation by PEN's London office, Sara Whyatt, program director for PEN's Writers in Prison Committee, sent Mignini and the Italian prosecutor a letter of protest on behalf of Spezi. After that, the police returned much of the coauthors' material, and Preston and Spezi finished the book.

Preston's publisher, Ornella Robbiati of RCS Libri, says she's not happy about the situation and doesn't want to be involved. ''Journalist Spezi and [the] main police investigator hate each other," says Robbiati, whose publishing company is Italy's largest. ''Why? I don't know. It's a complicated matter, this Monster of Florence. If they [Preston and Spezi] think they have discovered something useful to police and law, they should say something without insulting police and judges -- but it sounds too personal in my opinion, now."

At police headquarters in Italy in February, Preston says Mignini replayed a telephone conversation Preston had had with Spezi a few days before, which the detectives had intercepted in a wiretap. ''He threatened me with arrest if I didn't tell him what we were really doing as journalists and what the conversations were really about," Preston says.

At the end of the three-hour interrogation, Mignini told Preston his indictment would be temporarily suspended so that he could leave Italy but that it would be reinstated later.

''I had already decided not to assert journalistic privilege," says Preston. ''It's one thing to make a stand for freedom of the press in the US. I didn't feel like going to jail in Italy on principle."

According to Preston, several prominent judges in Italy have publicly criticized Mignini. Still, the experience has shattered Preston's sense of security about a country he lived in for four years and where several of his novels are set. ''I feel very pained that I may not be able to return to Italy," he says. ''While I am safe and sound back here in America, Spezi is still at grave risk. I was planning to go for the publication of our book in April. Now I don't dare set foot in the country."

Since returning to Maine, Preston has appealed to US Senator Susan Collins for help. A Collins spokesperson told Preston that the senator has given it her highest priority and has asked the State Department to find out what evidence Italian authorities have against Preston.

Preston also wrote to online literary organizations and bloggers, who posted his indictment story on their sites. Spezi sent the posting from the International Thriller Writers, an association of 150 prominent authors including Preston, to the Italian media. Within days, Italy's two largest newspapers carried prominent stories about Preston's interrogation and the support he has received from the online writing community.

Meanwhile, Preston is translating ''Dolci Colline di Sangue" into English and is in daily contact with Spezi. The translated book is projected for 2007 publication.

In an e-mail translated by Preston, Spezi wrote that he has been barred from writing about the Monster of Florence in his old newspaper, La Natione. He's engaged two lawyers, which he says has been ruinously expensive.

Last week, Spezi said, he discovered a microphone and transmitter in his car. He wrote: ''On the one hand I feel like I'm trapped inside a film of ''The Trial" by Kafka, remade by Jerry Lewis and Dean Martin. On the other hand, I am afraid -- afraid of what tomorrow might bring. To live with fear is an ugly thing. I am sleeping badly and I am afraid every time the doorbell rings."

An employee with Mignini's office said Mignini could not comment on the case. The Globe's requests for interviews with the Italian minister of the interior, Ispettore Castelli, went unanswered.

Preston's other world -- that of imagined crime -- continues unimpeded. His newest thriller ''The Book of the Dead," co-written with longtime collaborator Lincoln Child, will be out in June. As for his identity as an international writer and the freedom he expects to go with that privilege?

''I never expected them [Italian authorities] to go as far as they did," says Preston. ''And I felt that, as an American and a fairly prominent journalist and author, they would leave me alone. I was wrong."