Updated

A mysterious man toting a duffel bag has been identified as a key “person of interest” in the Brooklyn serial-killer case — after surveillance video showed him at one and possibly two of the three slay scenes, law-enforcement sources told The Post yesterday.

Cops said they are eager to talk to the mustached man — whom they dubbed “John Doe duffel bag” — about the killings of three Middle Eastern shop owners, each shot with the same .22-caliber gun over the last four months.

The unidentified man, who is middle-aged, white and balding, was most recently caught on surveillance video, duffel bag in hand, at around 6 p.m. Friday near the Flatbush store where owner Rahmatollah Vahidipour, 78, was found dead at 7:11 p.m., cops said.

Another video appears to show the same man near a Bensonhurst shop on Aug. 2 around the time its owner, Isaac Kadare, 59, was killed there, several sources said.

The duffel man has no known connection to the first murder — of shopkeeper Mohammed Gebeli, 65, in his Bay Ridge clothing store on July 6.

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“We want to identify the man known as John Doe duffel bag,” said NYPD spokesman Paul Browne.

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