The father of one of the American teens accused of killing a cop in Rome said his 18-year-old son is “distraught” and didn’t know his pal had a knife when they scuffled with the undercover Carabinieri.

Fabrizio Natale visited his son, Christian Natale-Hjorth, at the Regina Coeli Detention center on Wednesday and said the teen was “very emotional” about the July 26 fatal stabbing of 35-year-old Vice Brigadier Mario Cerciello Rega, who was stabbed 11 times, according to a statement obtained by Fox News.

“Gabriel is distraught with what happened and cannot come to terms with it,” Natale said in the statement. “We are deeply upset by his predicament while at the same time convinced of his innocence.”

“He only became aware of what actually happened after his arrest,” he said. “He is devastated by the carabinieri’s death and I for one, as a father, painfully feel his family’s grief.”

Natale-Hjorth and Finnegan Lee Elder, 19, who attended the same high school in Mill Valley north of San Francisco, were drunk and trying to score cocaine in Trastevere, a popular Italian party spot.

Authorities said they were incensed when they paid $100 for coke but got crushed-up aspirin. They stole the dealer’s bag and cellphone and demanded $112 and a gram of cocaine to return the bag.

But the dealer called police, who set up a sting near the Hotel Meridien Visconti, the four-star hotel the two teens were staying in — with Rega undercover at the scene.

A brawl broke out between the teens and the officers, and Elder allegedly stabbed Rega repeatedly with a 7-inch knife that police later recovered.

Police said Rega gasped “They stabbed me,” police said.

The two Americans fled but were tracked down at the hotel, where police recovered the alleged murder weapon stashed in the room’s fake-tile ceiling. They had return airline tickets with them.

Italian officials said Elder confessed to stabbing the officer, but claimed it was in self-defense, and Natale-Hjorth admitted punching another officer at the scene.

Questions later surfaced over how the two teens were being treated in Rome, with Italian prosecutors saying they would investigate after a photo of Natale-Hjorth — handcuffed and blindfolded in the local police station — was published in an Italian newspaper.

“I will refrain from commenting on the treatment to which Gabriel was subjected during his arrest,” Natale said of his son. “I understand the Italian authorities have initiated an inquest and I trust they will ascertain any responsibilities.”