Murder of Yara Gambirasio

On the evening of 26 November 2010, 13-year-old Yara Gambirasio left a sports centre in Brembate di Sopra, Lombardy, Italy, where she had dropped off a stereo for an upcoming gymnastics competition. She never reached her home, 700 meters away, and her family reported her disappearance to the Carabinieri. Despite a search involving hundreds of volunteers, her body was not located until 26 February 2011, when a man flying a model airplane found it by chance in a field near Chignolo d'Isola, about 10 kilometres from Brembate.

The decomposed body showed multiple deep, non-individually-lethal cuts and a head wound, all inflicted while the victim was alive. Investigators determined the cause of death was a combination of a head blow, the non-lethal cuts, and hypothermia from being left exposed in cold weather. No clear sign of sexual assault was found, though DNA traces were recovered from her leggings and underwear. Her funeral was held on 28 May 2011, led by Bishop Francesco Beschi of Bergamo.

The investigation initially and wrongfully targeted a young Moroccan man, Mohamed Fikri, who was arrested based on a mistranslated comment; he was later cleared after other translators reviewed the recording. Investigators subsequently focused on DNA evidence, identifying 11 distinct traces on the body, of which only two were ultimately attributed to individuals. Forensic scientists analyzed roughly 22,000 DNA profiles tied to a trace dubbed "Ignoto 1" (Unknown 1). The trail led through relatives, including Damiano Guerinoni and his deceased uncle Giuseppe Guerinoni, and eventually to Giuseppe Guerinoni's previously unknown illegitimate son. After DNA testing of a woman named Ester Arzuffi suggested one of her sons matched the profile, investigators identified Massimo Bossetti, a local construction worker, whose DNA was obtained via a breathalyzer test conducted to secretly gather a sample.

Bossetti was arrested on 16 June 2014 and pleaded not guilty, maintaining that his DNA evidence had been contaminated or fabricated and that stolen work tools may have been used by someone else. He stated that his tools "may be" his but that "the hand that killed her wasn't mine." Police maintained the DNA sample was "of excellent quality." His wife supported his alibi, though investigators did not find her account credible, partly based on phone recordings. A scientific adviser later raised questions in January 2015 about whether mitochondrial DNA matched nuclear DNA in the case, and Bossetti's defence repeatedly challenged the DNA evidence and requested his release, without success. Attention from the defence also focused on a gym instructor, Silvia Brena, whose blood was found on Yara's jacket sleeves.

On 1 July 2016, the Corte d'Assise of Bergamo sentenced Bossetti to life imprisonment. The Corte d'Assise d'Appello di Brescia upheld the verdict in July 2017, and Italy's Court of Cassation confirmed the life sentence on 12 October 2018. In November 2019, Bossetti's lawyers requested a review of the DNA evidence; this was denied in March 2021 because insufficient DNA remained for further testing. In December 2022, chief investigator Letizia Ruggeri became the subject of a separate investigation over allegations of misdirection and trial fraud; that case was dismissed in September 2024, with the judge finding she had not intentionally destroyed evidence.