Trieste, April 11 - A judge on Thursday confirmed the arrest of two 15-year-old Italian who turned themselves in to police in northern Italy Sunday and claimed they killed a man who allegedly tried to rape them. The pair, whose initials have only been released because of privacy laws protecting minors' identities, have been detained on suspicion of involuntary manslaughter. Investigators have since discredited the girls' version of events and believe they killed 67-year-old Mirco Sacher, a friend and neighbour, for kicks in a game that got out of hand. The Italian media have suggested they were inspired by a violent video game since they were reported to have told police about their fondness for Grand Theft Auto. Sacher's body was found in a field on the outskirts of the northeastern Italian city of Udine early on Sunday. The girls said the death was caused by their "reaction" to an attempted rape, adding that they fled the scene in the dead man's car. The pair then abandoned the car and turned themselves in. An autopsy has revealed Sacher suffered two broken ribs, leading a prosecutor to tell reporters one girl may have sat on their victim while the other allegedly strangled him. The girls used Sacher's ATM card before they were reportedly persuaded by friends to go to the police, the Italian media reported.