Rome -- An Italian police officer was mourned on Monday as the two American teens accused in his murder faced a drawn out legal process that could see them both jailed for life. Mario Cerciello Rega, a vice brigadier in Italy's Carabinieri police force, was fatally stabbed to death in Rome on Friday.

Seth Doane met friends of Cerciello Rega at his funeral near Naples on Monday as they paid their respects to the officer.

"My friend Mario was a good person," said Salvatore di Sarno, Mayor of Somma Vesuviana, where the slain officer lived. "He dedicated his life to the service of the weakest."

Adding to the emotion of the day was the fact that the officer was killed less than a month and a half after he was married in the same church where his funeral took place. The church wasn't big enough for the crowd of mourners, who formed a long line outside the stone building.

Cerciello Rega was stabbed to death on a Rome street, and Italian law enforcement officials have said the two American teenagers, Finnegan Lee Elder and Gabriel Christian Natale-Hjorth, confessed to being involved in the killing.

It started early Friday morning when Italian police say the Americans stole a backpack belonging to an Italian man, who had his cell phone in the bag. Officials have said the man called police and said the Americans had demanded a gram of cocaine and a hundred euros to give the bag back.

The Italian man set up a meeting point and tipped off the police, and plain clothes Carabinieri officers showed up.

Elder pulled out a knife, according to a statement by investigating judge Chiara Gallo on Monday, and stabbed the officer multiple times. Elder claimed in his statement to police that neither Cerciello Rega nor his partner had identified themselves as police officers, and he feared they plain-clothes officers were actually friends of the Italian backpack owner intent on attacking him.

Natale-Hjorth told police he was never aware of the knife purportedly carried by his friend.

But the statement released by the judge, permitting the extended detention of the teens, rejected the pair's claims, saying it was not possible that Elder did not understand the two men who had arrived on the scene were police, as they had identified themselves verbally multiple times and shown their badges, according to the slain officer's partner. The judge also said the multiple stab wounds inflicted on Cerciello Rega did not coincide with Elder's "legitimate defense" claim.

Elder admitted that Cerciello Rega never drew his service firearm. Neither American's body showed any signs of impact trauma or strangulation, in spite of Elder's claim to police that he felt the officer was strangling him.

As Doane notes, someone can be charged with murder in Italy if they were involved in a killing -- even if they didn't carry it out personally.

According to the judge, Natale said that after he and Elder arrived at the agreed meeting point with the owner of the backpack, they were approached by two men who were screaming, saying they were Carabinieri. Natale said that as he had no experience of Carabinieri in civilian clothes, he feared for his life so he pushed the other officer trying to hold him away and freed himself from his grip. Natale said he did not see what was happening between Elder and Cerciello Rega, and that only after they returned to the hotel and napped, Elder confessed to him that he had used a knife.

The warrant said the two teens were being held in solitary confinement at a Rome prison. They were schoolmates in the San Francisco Bay area, where teachers and students have said they were troubled and had disciplinary issues.

A photo of Natale-Hjorth blindfolded in the Carabinieiri station triggered debate and questions about the treatment of the teens in custody, but Rome's attorney general insisted the blindfold was placed briefly on the teen in an erroneous move by an officer prior to interrogation, which was carried out "free of duress."

"There is no place in any criminal justice system for a suspect to be blindfolded," Brian Claypool, an American criminal defense attorney told CBS News. He said he already sees similarities with the Amanda Knox case, an American teen accused of murder who was mistreated by Italian police during questioning.

"One saving grace for these teenagers in Italy is, much like what happened with Amanda Knox, if they are found guilty, they will have an opportunity to have an appeal of the entire facts that led to a decision of guilt," Claypool said.

But Doane says that whole process is likely to take many years. The first step is for an Italian court to determine whether there's enough evidence to proceed to trial -- and even that could take months.

The elder family issued a statement on Sunday saying they hadn't spoken with their son since Friday and that they were working with the State Department, which also had not had access to him as of Monday morning.