Il Mostro di Firenze (the Monster of Florence) is a serial killer responsible for the deaths of 14 people between 1974 and 1985.
These murders have resulted in the largest and most expensive manhunt Italy has ever known.
Florence law enforcement has investigated over 100,000 individuals, arrested dozens, and tried (and convicted) four men over the years.
While the citizens of Florence lived under a blanket of fear, the case also produced suicides, acts of violence, people digging up graves, séances, numerous cases of libel, and body parts being sent through the mail.
In the spring of 2006, the Italian police announced a breakthrough in the case, and arrested a new suspect—American novelist Douglas Preston.
Preston is probably best known for the best-selling thrillers he writes with Lincoln Child. He has also written a handful of solo novels, and six non-fiction books.
Ever since visiting Italy as a boy, he had always dreamed of living there. He was finally able to fulfill that dream in 2000, when he and his family relocated to Italy. Almost immediately, he began to work on a novel set in Florence.
He called it 'The Christmas Madonna'—the story of an art historian who helps to salvage ancient books and art work out of the Biblioteca Nazionale, after a major flood.
The historian finds an old manuscript describing the location of a lost Masaccio painting. The following day, the historian goes missing, and his murdered body is found outside the city. Twenty years later, his son comes looking for his father, only to find a horrifying secret instead.
To make sure he got the details of Italian police procedure, Preston met with Mario Spezi—a journalist who had covered Florence's crime beat for the past 30 years. It was here Spezi told Preston about the Monster of Florence.
Preston became so fascinated by the story that he dropped his novel and began to write a book about the case with Spezi.
Bringing fresh eyes to the case, Preston discovered it wasn't too hard to see why the real killer had never been caught. The prosecutions, he wrote, were not "based on what a good criminal investigation should be: the nitty-gritty of blood, hair, fibers, fingerprints, DNA, and reliable eyewitnesses." Since the first victims were discovered, officials appeared to have spent their efforts chasing conspiracy theories.
Since he was in America during the time of the murders, it may seem insane that he was charged with them. After his first interview, the police reduced Preston's charges to only being an accomplice to the murders. They now believed Preston's coauthor, Spezi, was the real killer.
It turned out the police had obtained a copy of their book before it was published, and—reading about how incompetent their investigative techniques had been—were now taking their revenge on the two writers. Spezi spent a month in jail before being allowed to contact a lawyer. The police told Preston to leave Italy, and to never return.
As of today, not much has changed. Although Spezi was exonerated, officials continue to harass him with wiretaps and unwarranted searches. Back in the States, Preston wrote a new book about the case, titled "The Monster of Florence." Similar to the one he wrote with Spezi, this one includes how both men became targets of the investigation: just two more victims of the Monster of Florence.