Rome (CNN)Friends, family and a grieving community gathered at a church in Rome Sunday to pay last respects to a fallen officer who was allegedly stabbed to death by two young Americans.Slain Italian police officer Mario Cerciello Rega with his wife on his wedding day in June. Rega's wake comes as police say they they are investigating a photo that appears to show one of the American suspects blindfolded at a police station in Rome. The image was leaked to the respected Italian newspaper, Corriere della Sera. Italian police have confirmed the authenticity of the photo, and told CNN that a two-pronged investigation has been launched into why the suspect was blindfolded and who leaked the photo to the press. Italian police officer Mario Cerciello Rega was killed on Friday in Rome. The two Americans, both from San Francisco, were arrested inside their hotel room in Rome. Police allege the boys stole a backpack from a man whom they had approached about buying drugs. The order and details of what happened next are still being investigated. However, police allege the Americans stole the backpack because they were sold crushed aspirin instead of cocaine. The teenagers subsequently answered the owner's cellphone, which they had also taken, and told him "they would not return the backpack without 100 euros and 1 gram of cocaine," police added. After police were contacted by the owner of the stolen bag, officers met the American suspects under the guise of retrieving the backpack, police said. Both the Americans are accused of assaulting the police officers, who reportedly identified themselves as law enforcement officers. Then one of the suspects took out a knife and stabbed the officer eight times before fleeing the scene, police said. The officers were unarmed, police added. The Carabinieri police force said in a statement that the Americans were arrested Friday night for "the crime of aggravated murder and attempted extortion." Alleged confession Police allege both Americans confessed to taking part in the assault, and say Elder confessed in the early hours of the interrogation on Friday to murder. Elder's appointed public prosecutor, Francesco Codini, said that during his court appearance Saturday his client "maintained his right to remain silent" in front of a judge.