Hector Quinones - who knew one of his victims from prison, police said - wounded a woman and terrorized another family member who found him in their third-floor walkup apartment after shooting the three men, police said.
Police found Carlos Rodriguez Sr., 52; and his son, Carlos Rodriguez, 24; shot to death in an apartment bedroom. Rodriguez Sr.'s father, Fernando Gonzalez, 87, was dead in a bathroom, they said.
Police said Quinones, 44, had recently been released from prison after serving time for manslaughter, and had known the elder Rodriguez from prison. The elder Rodriguez had served sentences for drug convictions, police said.
The family lived on a busy street of bars and eateries in a tree-lined residential neighborhood a few blocks from Central Park and the American Museum of Natural History.
Police recovered a semiautomatic handgun in the apartment in the rear of the walk-up building, chief police spokesman Paul Browne said.
Giselle Rodriguez - who was married to Carlos Rodriguez Sr. and the mother of the 24-year-old man - and her daughter came upon Quinones after the men had been shot, police said.
Quinones held both women at gunpoint before the daughter, Lyanis Rodriguez, broke free and locked herself in the bedroom with her father and brother's bodies, police said. Quinones wounded Giselle Rodriguez - who was hospitalized in stable condition Thursday night
before both women managed to leave the apartment, police said.
Quinones fell to his death from a fire escape into a cement courtyard below, police said.
The shootings rattled the upscale neighborhood, as pizzeria owners and priests watched the wounded woman wheeled into an ambulance.
Police had the entrance to the building and part of the block cordoned off. Scores of onlookers crowded the sidewalks, and dozens of police cars lined Amsterdam Avenue.
This is a great, yuppified neighborhood," said Gene Silvers, who was pumping air into his bicycle tires across the street from the shootings. "Not dangerous."
Hispanic neighbors planned a Spanish-only prayer service for the victims later Thursday.
Hector O'Neal, who said he was the family's landlord, said police had asked him not to speak about "la familia familia Rodriguez." "I can't talk to anybody right now," he said.
Dimitrios Vezyrakis said the family were "nice people, just normal people who came in for pizza" across the street.
Darryl Gamble, who owns a women's clothing boutique on the ground floor, said he heard no commotion coming from the apartments.
"I think that most of the tenants have been there for years," Gamble said. He said he had no problems with his neighbors, outside of "the usual, New York noise, a few leaks."