Funeral for 'hero' Italian officer Mario Cerciello Rega allegedly killed by US teens to be held where he was married

A newlywed Italian police officer who authorities allege was stabbed repeatedly and killed in a confrontation with two American teenagers in Rome is set to be mourned on Monday at a funeral in the same church where he was married a little over a month ago.

The slaying of Deputy Brigadier Mario Cerciello Rega, a member of the famed Italian Carabinieri paramilitary police force, has sent shock waves from Italy to Northern California, where the two suspects, Finnegan Lee Elder, 19, and Gabriel Christian Natale-Hjorth, 18, are from.

On Sunday, hundreds of people turned out to honor Cerciello Rega, whose body lay in repose at a chapel in central Rome.

Italian Prime Minister Giuseppe Conte called Cerciello Rega's death a “deep wound for the State” while Deputy Prime Minister Matteo Salvini praised the officer as "a hero."

Flowers and notes of condolences from friends and strangers of the slain officer piled up on Sunday outside the Carabinieri headquarters in Rome. Sandro Ottaviani, the station commander, told reporters that Cerciello Rega was a beloved member of the force who "always thought about his neighbors, both during the service shifts and when he didn't wear the uniform."

"He used to make pilgrimages to Lourdes and Loreto to help the suffering people every week," said Ottaviani, referring to two major Catholic pilgrimage sites. "Without telling anyone, he volunteered. Not only does a brave Carabinieri die, but a great man."

The 35-year-old Cerciello Rega and his wife, Rosa, were married on June 19 at a church in his hometown of Somma Vesuviana, near Naples. His wife will return to the church on Monday a widow after just 43 days of marriage to mourn her husband's death.

Somma Vesuviana Mayor Salvatore Di Sarno has proclaimed Monday to be a "day of mourning" for the city.

Cerciello Rega, who had just returned to duty from his honeymoon to Madagascar, responded with his partner to a call about 3 a.m. on Friday that turned fatal.

Elder and Natale-Hjorth, both graduates of Tamalpais High School in the San Francisco suburb of Mill Valley, were allegedly trying to buy drugs before the slaying, but were sold a fake substance, a police spokesman told ABC News.

They then allegedly robbed a man of his backpack, police said. The robbery victim is not believed to be the man who allegedly sold the American tourists the fake drugs, but it remained unclear on Sunday whether he is connected to the drug dealer, officials said.

Elder and Natale-Hjorth allegedly demanded that the man pay them "100 euros and 1 gram of cocaine" to get his backpack returned, a police spokesman said. The man agreed, but he also reported the alleged extortion attempt to police, according to the police spokesman.

Cerciello Rega and his partner, both in plainclothes, responded to the complaint and confronted the suspects, police said. A scuffle broke out and Cerciello Rega was stabbed eight times, allegedly by Elder while Natale-Hjorth allegedly punched Rega's partner repeatedly, according to police reports made public on Saturday.

The suspects were captured on surveillance video running from the scene with the stolen backpack, police said. They were tracked down at their hotel near Rome's Tiber River, police added.

The two were questioned by police for hours and when "faced with overwhelming evidence, they confessed," the Provincial Command of Rome said in a statement that was translated from Italian.

On Sunday, a leaked photo of Natale-Hjorth, blindfolded and handcuffed while in the custody, was published by Italian newspapers, prompting questions about the pair's confessions.

Italian provincial police Cmdr. Francesco Gargaro told the Associated Press that Natale-Hjorth was "illegally blindfolded" before he was interrogated. He said the suspect was blindfolded "for a very few minutes, four or five" before he was questioned.

Gargaro said the officer who blindfolded the suspect made a "mistake" and that an investigation of the incident has been launched.

Police said that in addition to the security footage of the suspects running from the scene of the slaying, investigators found a knife believed to be the murder weapon and bloody clothes hidden in the ceiling of their hotel room.

Elder and Natale-Hjorth, who are both U.S. citizens, were taken into custody on suspicion of aggravated murder and attempted extortion, and are being held at the Regina Coeli district jail in Rome, police said.

On Saturday, Elder's family, which has a home in San Francisco, expressed "our deepest condolences" to Cerciello Rega's loved ones, saying they "are shocked and dismayed at the events that have been reported."

Elder's parents released a new statement on Sunday saying they have not been able to speak to their son since he called them from a police station following his arrest on Friday.

"We are working with the U.S. State Department, but they have not been granted access to Finn," the parents' statement reads. "What we know so far is that Finn has been appointed an Italian public defender to handle his case. We plan to go to Rome as soon as the State Department assures us we will be able to see our son."

The statement added that the parents are aware of the officer's funeral plans and "wish to be respectful of his family and friends at this devastating time."

The parents' said in the statement: "As any parents would be, we are deeply concerned for our son and are heartened by the expressions of sympathy and support from our friends and neighbors."

Elder's Italian lawyer, Francesco Codini, declined to answer questions from reporters about the allegations against the teenager, saying, "Out of respect for the military man who has died we do not want to say anything else."

It remains unclear if Natale-Hjorth has an attorney. His family has yet to make a statement.

Gloria Keeley, a neighbor of Elder in San Francisco, said she was shocked that Elder could be suspected of murder.

"I've never seen him violent in any way. I've known Finn since he was born," Keeley told ABC station KGO-TV. "The nicest guy. One of the nicest neighbors I have."

ABC News' Ariane Nalty contributed to this report.