A 24-year-old man was arrested in the shooting death of the reputed boss of the Gambino crime family, New York police said.
Anthony Comello was arrested in New Jersey in the death of Francesco Cali last week in front of his Staten Island home, said Chief of Detectives Dermot Shea, who stressed that the investigation is in its early stages.
"There are multiple, multiple angles that we are exploring," Shea said.
"Was the person paid to do it? Were others conspiring to do this crime?"
The 53-year-old Cali, a native of Sicily, was shot to death by a gunman who may have crashed his truck into Cali's car to lure him outside.
Shea said Cali was shot 10 times.
Police have recovered the truck but have not recovered the gun used in the murder.
Asked about Comello's arrest record, Shea said he "crossed paths in some limited circumstances with the NYPD" including getting a parking ticket on Staten Island the day Cali was killed.
Federal prosecutors referred to Cali in court filings in recent years as the underboss of the Mafia's Gambino family, once one of the most powerful crime organisations in the US.
News accounts since 2015 said he had ascended to the top spot.