Two 19-year-old Americans have been arrested in Rome over the murder of an Italian police officer, police there said on Saturday.

The police authorities said the two were arrested on Friday night for “the crime of aggravated murder and attempted extortion.”

The suspects have been named as Christian Gabriel Natale Hjorth and Elder Finnegan Lee. Both are said to be from San Francisco, California.

Italian police officer Mario Cerciello Rega was stabbed eight times at 2AM local time on Friday in Rome. Police said the incident took place near a hotel where the two boys were staying.

A police statement said surveillance footage and witness testimonies had helped the Capitoline Investigative Unit to identify the two responsible for the “heinous crime.”

The two Americans were arrested inside their hotel room.

“They were already ready to leave the country,” police said. “During the search of the hotel room, which was occupied by the two detainees, the murder weapon was found and seized, a knife of considerable size, cleverly hidden behind a ceiling panel, as well as the clothes worn during the crime.

“The two, once at the station, were interrogated by the Carabinieri, under the direction of the magistrates of the Public Prosecutor of Rome, in the face of overwhelming evidence, they confessed to the charge.”

U.S. authorities are yet to respond to the arrest.