Authorities say the suspect may have been ejected from the Mansion nightclub in Mount Vernon shortly before the 4:26 a.m. shooting on Christmas Day.
Mount Vernon Mayor Richard Thomas said in a statement Sunday that the establishment's owner, O'Neal Bandoo, was killed. He says the name of the second person who died is being withheld pending family notification.
Police say the shooting victims were found in the lobby and on the street outside the club.
Officials haven't named the suspect, but say he is a Bronx resident with a pending attempted murder case.
Witness Cleveland Douse tells The Journal News that 200 people were in the club during the shooting.