The Carabinieri police force said in a statement that the pair were arrested Friday night for “the crime of aggravated murder and attempted extortion.”
Police named the suspects as Christian Gabriel Natale Hjorth and Elder Finnegan Lee, and said both were from San Francisco, California. Photos of the pair have not been released.
Italian police officer Mario Cerciello Rega was stabbed eight times at 2 a.m. local time on Friday, in the Prati neighborhood of Rome on Via Pietro Cossa, near the hotel where the two young men were staying, police said. Officer Rega was declared dead at 4:30 a.m.
The police statement said surveillance footage and witness testimonies had allowed the Capitoline Investigative Unit to identify the two responsible for the “heinous crime.”
The two Americans were arrested inside their hotel room in Rome.
“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.”
Only one of the men is accused of stabbing the officer, but both admit to taking part in the fracas, police said.
Police also noted that the Americans had stolen a backpack from an Italian citizen shortly before the murder. The suspects subsequently answered the owner’s cellphone, which they had also taken, and told him “they would not return the backpack without 100 euros and 1 gram of cocaine,” police added.
After police were contacted by the victim, officers met the American suspects under the guise of retrieving the backpack.
They subsequently identified themselves as law enforcement officers, upon which one of the suspects took out a knife and stabbed the officer eight times before fleeing the scene, police said.
The police said that the pair “did not hesitate to engage in a scuffle which culminated in the tragic deadly wounding of Mario Rega Cerciello.”
Italian state police (Polizia di Stato, in Italian) also paid tribute to the murdered officer shortly after news of his death emerged, with a number of police cars sounding their sirens outside the Carabinieri headquarters in Rome.
The investigation into the officer’s murder is ongoing.
CNN has contacted the US Embassy, which referred questions to the US State Department. CNN has not yet received a response from the State Department.
CNN’s Matthew Robinson contributed to this report.