Rome — An American teenager was illegally blindfolded before he was interrogated as a suspect in the slaying of a newlywed police officer in Rome, an Italian police commander said Sunday after the emergence of a photo showing the young tourist restrained with handcuffs and with his head bowed.

Californian Gabriel Christian Natale-Hjorth, 18, was blindfolded "for a very few minutes, four or five" on Friday just before he taken to the interrogation in a police station about the fatal stabbing, Rome Provincial Commander Francesco Gargaro told The Associated Press in a phone interview.

Natale-Hjorth and another suspect from California, 19-year-old Finnegan Lee Elder, remained jailed while Italians lined up outside a chapel to pay respects to Deputy Brigadier Mario Cerciello Rega, an Italian paramilitary policeman was fatally stabbed in Rome on Friday while investigating the theft of a bag with a cellphone.

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CBS News correspondent Seth Doane reports Natale-Hjorth and Lee Elder "confessed their deeds" and are being detained for aggravated murder and attempted extortion.

In this combo photo released by Italian Carabinieri, Gabriel Christian Natale Hjorth, right, and Finnegan Lee Elder, sit in their hotel room in Rome. Italian Carabinieri via AP

A 35-year-old newlywed Carabinieri officer, Mario Rega, was stabbed to death on a Rome street early Friday morning. The Carabinieri said their investigation reveals that shortly before the murder, the two young men stole a backpack from an Italian man, and then threatened him during a phone call that they would not return the backpack unless they were given 100 euros and a gram of cocaine.

The man reported the incident to the Carabinieri, who came to the meeting to stop the criminals. But a scuffle unfolded, and the Carabinieri officer was stabbed to death. An autopsy showed he had been stabbed 11 times. The coroner concluded that the policeman bled to death, according to Italian news reports.

Two Italian Carabinieri stand near a blood-stained street where their colleague, Carabiniere Vice Brigadier Mario Cerciello Rega, was stabbed to death by a thief in Rome, Friday, July 26, 2019. AP

Investigators allege Elder knifed the policeman during a struggle after Cerciello Rega and his partner, both plainclothes officers, identified themselves as police.

Law enforcement found the Americans in their hotel room at Le Méridien Visconti, ready to leave Italy. Police say they searched the room and found the murder weapon — a "knife of considerable size," hidden behind a ceiling panel.

Italian newspapers on Sunday published a photo of Natale-Hjorth with what appears to be a scarf covering his eyes and with his arms handcuffed behind his back as he sat in a chair at a police station. Police and prosecutors are conducting separate investigations of the blindfolding.

Blindfolding of a suspect "is illegal. It's not allowed," Gargaro said. The officer who put the blindfold on committed a "mistake" but did so to prevent Natale-Hjorth from seeing documents related to the investigation, the commander said.

Natale-Hjorth had been brought in handcuffs to the station-house from his hotel, Gargaro said. He was interrogated by police and prosecutors without a lawyer there since he had not been formally detained as a suspect and Italian law does not allow an attorney's presence at that stage, the commander said.

But Rome's prosecutor general, Giovanni Salvi, said in a statement that there was indeed a lawyer present during the actual interrogation. It was not immediately clear if Gargaro might have been referring to the time spent while waiting for the interrogation.

Salvi, as Gargaro did, also stressed that the two suspects "were brought to the interrogation physically free, without blindfolds or handcuffs." Salvi said the interrogation, by two magistrates, "was recorded and entirely transcribed. The defendants were advised of their rights."

The officer who placed the blindfold on was being transferred to a different unit, Gargaro said. The Carabinieri were also investigating who took the photo and how it was leaked.

Elder's lawyer, Francesco Codini, did not reply to request by the AP for comment. Natale-Hjorth's lawyer could not be reached.