Several officials said preliminary information suggested that the killing was not related to organized crime, but one cautioned that the inquiry was still in its early stages. The unidentified man had not been charged.

The official, who spoke on the condition of anonymity because he was not authorized to speak publicly about the case, said the man, 25, was taken into custody on Saturday morning in New Jersey and was being questioned by authorities.

Francesco Cali, the reputed boss of the Gambino crime family, was fatally shot outside his home on Staten Island on Wednesday night.

Officials said the unidentified man gave conflicting statements, and detectives were investigating whether he had been dating Cali’s daughter and had been instructed to stop seeing her.

Cali, 53, was shot six times. Police said they received a report about the shooting outside 25 Hilltop Terrace in the Todt Hill section of Staten Island around 9:20 p.m.

The gunman first struck Cali’s car, and then went to the front door of his home and rang the door bell. An image of his face was captured by a surveillance camera, another law enforcement official said.