The officers unloaded 16 rounds in the shadow of the Empire State Building at a disgruntled former apparel designer, killing him after he engaged in a gunbattle with police, authorities said.
Three passersby sustained direct gunshot wounds, while the remaining six were hit by fragments, according to New York Police Commissioner Ray Kelly. All injuries were caused by police, he said Saturday.
One officer shot nine rounds and another shot seven.
Police identified the gunman as Jeffrey Johnson, 58, who was apparently laid off from his job as a designer of women's accessories at Hazan Import Co. last year.
Johnson, who served in the U.S. Coast Guard in the mid-1970s, had two rounds left in his pistol. It holds eight, Kelly said.
Police identified the slain co-worker as Steven Ercolino, 41, who had apparently filed a prior complaint against his assailant, claiming that he thought Johnson would eventually try to kill him.
Both men had filed harassment complaints against each other in April 2011, Kelly added.
Ercolino was listed as a vice president of sales at Hazan Import Corp., according to his LinkedIn profile.
"It's not something that should happen to a loving person like that," said his brother, Paul. "He's going to be so missed by everybody. He was a light of so many lives."
His longstanding dispute with the gunman "apparently centered on the fact that Ercolino was not selling -- at least in Johnson's opinion -- as much of his product ... as he wanted him to," Kelly said.
The suspect lost his job last year at Hazan "as a result of downsizing" but continued to return to the company regularly, engaging in "a confrontation with Ercolino virtually every time he went back."
The violence erupted Friday morning just as visitors began to queue up to ascend the famous New York skyscraper in one of Manhattan's busiest neighborhoods.
Six of the injured were treated and released at hospitals by Friday evening, while three others remained hospitalized, Kelly added.
One of those wounded, Erica Solar, was on her way to get a cup of coffee at Dunkin' Donuts when a bullet tore through the back of her leg, her brother said. The Manhattan receptionist is being treated at the city's Bellevue Hospital.
Experts: Empire State Building shooting won't keep tourists away
Others like Robert Asika, a 23-year-old city tour guide, were on their way to work and got caught in the crossfire.
"When I turned around, I saw a guy reach in his suit and he pulled out a gun," he told CNN affiliate WCBS-TV. "I guess he shot at the police officer. And the police officer shot him. And one of them shot me in the arm, and I fell."
Witnesses recount chaotic, unsettling scene
Irene Timan recalled to CNN affiliate WABC how she was walking down West 33rd Street and chatting with Ercolino on Friday morning, when she spotted Johnson.
"I was like, 'Oh my God, that's Jeff Johnson.' And I was like, 'He's going to kill him, he's going to kill him, I know he's going to kill him,'" said Timan, who knew there was "bad blood" between Johnson and Ercolino but didn't know why.
Then, as Ercolino was talking to Timan in mid-sentence, Johnson fired at him -- "right next to me," she recalled.
Kelly, the police commissioner, said that Johnson -- who was wearing a business suit and carrying a briefcase as he waited -- shot Ercolino once in the head and then in the torso.
An emotional Timan said Saturday that she has been replaying the incident "over and over in my mind. And I thought, 'Maybe you could have kicked the gun out of his hand and Steve would have only gotten shot once instead of five or six times.' ... I just ran, I didn't know what else to do."
Johnson then walked east, before eventually turning north. A construction worker was among those who dashed after the gunman after the initial gunshots. Eventually, the worker alerted two police officers in front of the Empire State Building that the suspect "just killed a man around the corner," Kelly said.
The police commissioner said the suspect pulled his gun out of his briefcase as the officers approached, pointing at them. The officers then fatally shot Johnson.
A brief surveillance video released Friday night by police shows the man walking behind a large planter on a busy street. He appears to point something as two officers approach, coming to within a few feet of him. Then, as bystanders run in all directions, the man falls abruptly to the ground after apparently being shot.
Witnesses said police shot Johnson at least three times.
"I heard the gunshots," said Anika Basu, who was on a bus near the building when the shooting happened. "I looked toward the left and saw three people fall. ... The whole entire crosswalk emptied and people were running.
When she heard the shots and saw people running, this time toward her, Timan said she feared Johnson was "going on a shooting spree."
"And I really thought he was coming back for me," she said.
Police say Johnson used a semiautomatic handgun and was carrying extra ammunition in his briefcase. He purchased the weapon legally in 1991 in Florida but did not have a permit to carry it in New York City.
The former Manhattan resident did not appear to have had a criminal record, but authorities were still checking, Mayor Michael Bloomberg said.
Johnson's neighbor, Gisela Casella, described him as a quiet animal lover whose death left her "shocked."
"He was the nicest guy. He must have snapped or something. I don't know," she said.
His landlord, Guillermo Suarez, said he lived alone and that he'd seen Johnson leave the building around 8 a.m. in a suit.
By around 9 a.m., the shootings had prompted local and federal authorities to close several streets around Fifth Avenue and West 34th Street, snarling traffic in the heart of Manhattan.
What to know about Empire State Building
The Empire State Building is one of the most famous skyscrapers in the world and one of New York's best-known tourist attractions.
Each year, about 4 million people visit the building's two observation decks. At more than 1,453 feet tall, the landmark building reaches more than a quarter-mile into the sky.