Almost 20 years after the last murder blamed on the "Monster of Florence", investigators have reopened the case because they suspect a Satanic cult ordered the killings and kept body parts as prizes.
"The refrigerator of horror", was Friday's headline in Il Messaggero newspaper, referring to new witness reports of female genitalia and body parts in the fridge of a plush Tuscan villa.
The villa was rented by a doctor, thought to have drowned in a Tuscan lake in 1985. But when authorities recently discovered he was a suspected Satanist and had actually been murdered, they reopened their files, a judicial source told Reuters.
Investigators now suspect the doctor was part of a clan that ordered the "Monster" to kill eight couples.
The victims were shot during romantic trysts in the picturesque Tuscan countryside between 1968 and 1985 and many suffered gruesome sexual mutilations.
A farm labourer of below-average intelligence was initially convicted in 1994 for the murders, in a sensational mystery which caught the attention of the author of "Silence of the Lambs".
The labourer, Pietro Pacciani, was acquitted in an appeals court in 1996 but was ordered to stand retrial. He died in 1998 at the age of 73 before the retrial could get underway, but two men were convicted of aiding him in the 1990s.
Prosecutors now think there were two tiers to the killings, and this week began a new probe into Tuscan higher society.
"The eight double homicides were carried out according to a criminal plan on two levels," the source said, citing the search warrant issued by prosecutors.
"The execution was entrusted to (Pacciani and his friends) but a group of people who celebrated rituals and black magic put the arms in their hands," the warrant said.
Authorities have now formally placed a 60-year-old pharmacist under investigation, with police seizing pornographic videos and books from his home.
A respected Florentine dermatologist, a businessman and a lawyer are also now being questioned, the source said.
The reopening of a case that shocked and mesmerised Italy for decades has shattered the peace of Chianti's rolling hills.
Thomas Harris, the American author of best-selling serial killer novel "Silence of the Lambs" with its cannibalistic character Hannibal Lecter, was fascinated by the case and attended the initial trial to "work and gather data".