Police also revealed that the gunman was carrying about 100 rounds of ammunition in five magazines when he set out on the bloody rampage through the apartment.
Ali Akbar Mohammadi Rafie fired several rounds early Monday before he used his rifle to kill himself on the roof the apartment building where four members of the band Yellow Dogs lived together, police said. Afterward, investigators recovered 81 unfired rounds, some of them in magazines stashed in a guitar case found on an adjoining rooftop.
Kelly Tuesday said investigators have zeroed in on the motive behind the murders. "We still believe the dispute involved money," said Kelly. "Raefe, the individual who did the shooting, was apparently ejected from the group a year ago. His relatives were sort of petitioning the members of the band to bring him back in. He was reportedly despondent over the fact that he wasn't in the band. "
Records show the Spanish-made assault weapon used in the shootings was purchased by someone else at an upstate New York shop that went out of business in 2006, said Kelly.
"We don't know precisely how Rafie obtained it," he said. Fans and friends were horrified.
The gunman's body was found on the rooftop of the band's live-in recording studio with a single, self-inflicted, gunshot wound to the head.
Inside the building were the bodies of three other musicians, all had been shot to death.
Two of the victims were members of "The Yellow Dogs," punk rockers who emigrated from Iran just three years ago.
"We don't want to change the world; we just want to play music," a band member said on CNN.
The dead were identified by police as: Soroush Farazmand, is brother, Arash, and their friend, Ali Eskandarian, and the gunman, Rafie.
Detectives say Rafie used an assault rifle.
He shot and killed one of the musicians through a window, then broke into the building, wounding another man before murdering the others and taking his own life.
The group's manager told Eyewitness News, "The gunman was not part of the band. He was in another band. They played together a couple times last year. But [he was] never part of the Yellow Dogs Band."
Regardless of the motive, the violence has left neighbors badly shaken.
"These were good neighbors, it's just unbelievable," said Martin Greenman, a neighbor.
The Yellow Dogs played recent gigs in the New York indie rock scene at venues like the Knitting Factory and Brooklyn Bowl.