Investigators say evidence collected so far at the scene of a fatal shooting outside the Empire State Building suggests the gunman who killed a former co-worker did not fire at police officers before they killed him, contrary to earlier reports.

However, dramatic surveillance video does show the shooter, 53-year-old Jeffrey Johnson, pointing his gun at two New York City police officers, who quickly fired at him.

The video shows Johnson dropping his briefcase, falling to his knees and then collapsing on the sidewalk.

Just moments earlier, around 9 a.m., Johnson had shot and killed his former co-worker, Steven Ercolino. He was trying to flee the scene when two uniformed officers approached him.

About a dozen people, including children, scattered in all directions when gunfire broke out. Nine bystanders were wounded or grazed by the gunfire, but all are expected to survive.

They were likely were hit by police officers' stray bullets, as some of them ricocheted. The two officers fired 16 shots.

The Associated Press reports that ballistic evidence does not support what at least one witness told police: that Johnson fired at the two officers before they killed him.

Investigators said Johnson's weapon held seven rounds. He fired five times at Ercolino. One round was still in the gun, and one was ejected when officers secured it.

Ercolino, a 41-year-old vice-president of sales at Hazan Imports, where Johnson used to work before he was laid off, was shot point-blank in the shadow of the Empire State Building.

"Jeffrey just came from behind two cars, pulled out his gun, put it up to Steve's head and shot him," Carol Timan, whose daughter, Irene, was walking next to Ercolino, told The Associated Press.

The AP reports that Johnson and Ercolino had traded accusations of harassment when Johnson worked at Hazan.

New York City Police Commissioner Ray Kelly said the officers who caught up to Johnson had "a gun right in their face" and "responded appropriately."

"These officers, having looked at the tape myself, had absolutely no choice," he said.

Police said Johnson purchased the gun legally in Florida more than 20 years ago, but did not have a permit to possess it in New York City.

"New York City, as you know, is the safest big city in the country, and we are on pace to have a record low number of murders this year," Mayor Michael Bloomberg said. "But we are not immune to the national problem of gun violence.”