When a gunman handed a license plate to Gambino mob boss Francesco “Franky Boy” Cali moments before allegedly shooting him in cold blood, he left behind fingerprints that identified him, a senior law enforcement official told The Daily Beast.

The prints helped police track 24-year-old Anthony Comello to a summer home in Brick Township on New Jersey’s south shore three days after Cali was gunned down in front of his Staten Island home.

In a press conference announcing his arrest, NYPD Chief of Detectives Dermot Shea said Comello is awaiting extradition and will be charged with murder when he arrives on Staten Island. The Ocean County Department of Corrections said Comello was being held on murder charges at the request of the NYPD.

“This is far from over,” Shea said. “The questions are was he acting alone?Was he acting with other people? Was someone else involved?”

Police recovered the pickup truck at the home in New Jersey, and are looking to see if damage on the vehicle matches that on Cali’s, police said. The have yet to recover the murder weapon.

Shea said police are still working on a motive for the killing, but one official said police believe the shooting is not related to the mob. Comello, who was described by two officials as “nuts,” allegedly shot Cali at least six times following a dispute over his niece.

Cali, a Brooklyn-raised gangster who’s headed the Gambino crime family since 2015, had told the suspect to stay away from his niece, who was inside the mob boss’ home at the time of the killing, the official said.

The break in the case comes after police said they recovered surveillance video from a camera outside Cali’s home that showed the suspect repeatedly backing his pickup truck into the mob boss’ Escalade Wednesday night, knocking off the back license plate.

Once Cali goes outside, the video shows the two men engaged in a discussion. At one point, the suspect handed Cali the license plate, sources previously told The Daily Beast. As Cali placed the plate in the back of his SUV, the suspect, who was wearing a baseball cap and hoodie, pulled out a 9mm handgun and fired 12 times, peppering Cali with at least six bullets. The mob boss later died at Staten Island University Hospital.

During the course of the investigation, police scrubbed further back on the surveillance video timeline and saw Comello lurking on the porch outside Cali’s home earlier in the day, an official said Saturday. At one point Comello looks directly into the camera and investigators are able to get a clear look at his face, the official said.

The official said investigators are considering the possibility that the man rang the door bell and was told to go away, leading him to back the pickup truck into Cali’s SUV.

A second senior law enforcement official said that Comello has no clear ties to organized crime and police are working to determine if the car accident was actually just an accident, or staged.

Comello, who also has a home on Staten Island, was arrested in New Jersey by the New York-New Jersey regional task force of which the NYPD is a member, authorities said.

Comello was questioned multiple times by investigators before he asked for an attorney, Shea said. It was not immediately clear if Comello had retained an attorney.

Records submitted to the state court system show that Comello has been charged with one count each of murder, criminal possession of a weapon and assault and a case has been docketed by the Staten Island District Attorney.

Investigators including the NYPD, Staten Island District Attorney’s office, and authorities in New Jersey have executed more than one search warrant and anticipate executing additional search warrants, Shea said.

—Victoria Albert contributed reporting