Matteucci was born in Turin on April 24, 1962. His father, who had convictions for theft and handling stolen goods, left within months of his birth, and his mother sent him to an aunt in Foggia until he was five. He said in custody that his mother had worked as a prostitute and had made him witness her encounters, and that he killed to punish her and to rid the world of filth. He later lived in the Aosta valley, married, had a son, and worked as a stonemason.
On April 30, 1980, aged eighteen, he killed Domenico Raso, a shopkeeper in Aosta, of whom he said afterwards that he had no reason to exist. That killing was not solved at the time and no one was charged with it. The Italian press called him il mostro di Aosta, the Monster of Aosta.
His marriage broke down and from 1992 he began going to prostitutes. He killed three women: Daniela Zago, Clara Omoregbee and, on May 12, 1995, Albana Dakovi, an Albanian woman. He stabbed them or beat them with a wrench after sex, dismembered and burned the remains in a drum, and committed acts of necrophilia, which the investigators established afterwards. A fourth woman survived an attempt on her life.
He was under a court order at the time of the last killing. Arrested that April for car theft, he had been required to report to the police at Saint-Pierre and not to leave the area between Arvier and Aosta. After killing Albana Dakovi he put her body in his van and drove to Saint-Pierre to sign the register.
He was caught by an anonymous letter. Dakovi's pimp had watched her get into an Iveco Daily van and had written down the plate, and sent the number to the police. Matteucci was arrested on June 26, 1995 and, after some days, confessed to all four killings.
A psychiatric report found him partially incapable of understanding and willing his actions, and socially dangerous. On April 16, 1996 the Corte d'assise at Aosta sentenced him to twenty-eight years' imprisonment followed by three years' detention in a judicial psychiatric hospital. Accounts of the two instances differ on which killings were held proved at first instance and which on appeal; what is agreed is that he was ultimately held responsible for all four and that the sentence reflected the finding of partial insanity.
He left prison on March 9, 2017, aged fifty-five, having served almost twenty-two years, and was transferred to a secure psychiatric facility rather than released outright; he had spent the last part of the sentence in a psychiatric hospital at Reggio Emilia. In 2022, in a therapeutic community, he met his son for the first time in twenty-five years and apologised to him.
He is the only known serial killer of the Valle d'Aosta. The entry that stood here had the killings running from 1992, placed some of them in Puglia, and said he had been convicted in 1980 and released. None of that was right: the 1980 killing went unsolved, the crimes were all in the Aosta valley, and the fifteen-year gap between the first killing and the rest is the striking fact about the case.