50 years ago, on the night of August 21-22, 1968, an Italian killer struck for the first time. The serial killer "Mostro di Firenze" (Monster of Florence) targeted a couple in love parked in their car in the famous "Lovers' Lane" in Signa, a small town west of Florence. Both were shot with a Beretta 22 caliber, series 70, using Winchester long rifle bullet series H. On the night the couple was killed, Barbara Locci's son, Natalino Mele, was fast asleep in the back seat of the car while the "Monster" committed his first heinous crime. Over the years, the serial killer would become infamous for his pattern of killings and would be responsible for 16 murders. For the murder of Barbara Locci and her lover, Stefano Mele was charged and sentenced to 14 years in prison.

On September 14, 1974, the serial killer strikes again, shooting and stabbing a young couple in Borgo San Lorenzo. The monster would kill again on June 6, 1981, October 22, 1981, June 19, 1982, September 9, 1983, July 29, 1984, and for the last time on September 8, 1985.

The police investigation and the trial were the longest in Italian history and several theories were developed: The investigators began to pursue many possibilities that led them to convict Pietro Pacciani and his friends (known as the "picnic companions") and to arrest at various times other suspects who were later released. The investigators also announced that the crimes could be linked to a satanic cult. However, 50 years after the first murder, the judiciary announces unfounded verdicts (2018).