Two officers required treatment for friendly-fire graze wounds from ricocheting bullet fragments or debris.
Johnson, calling the two "very lucky," said police officials were concerned about the number of rounds fired. He said that some officers would be retrained as a result and that the department was looking at weapons training overall.
The incident was the year's ninth fatal shooting by Philadelphia police. Last year, police were involved in 22 fatal shootings, including two outside the city, the most since such recordkeeping began in 1980.
Residents told a different, more detailed story about the death of Miller on the corner of Tasker and Taney Streets.
They said the barrage of gunfire was unleashed when one officer, who was standing about 30 yards away on Taney and apparently out of the view of the other police on Tasker Street, opened fire after telling the man to drop the gun.
Some residents said the officers on Tasker were attempting to coax Miller, who was known as "Butta," to drop the gun when they heard the first shot and opened fire themselves.
"He spooked the other cops," said Clarence Sayles, who said he spent a half-hour with another neighbor trying to get Miller to drop the gun before police arrived.
"The cops on Tasker Street were doing the best they could," he said. "They almost got him to drop the gun."
Johnson acknowledged that some of the officers might have fired because they thought "they were being fired on by this individual."
A trail of evidence circles marking where shell casings apparently fell led from where residents said the officer on Taney fired to the corner.
Some neighbors said the officer, who, like Miller, was black, emptied his clip and reloaded. They said other officers hustled the patrolman into a car and away from the scene shortly after the shooting.
Johnson said that officers had been on the scene for four or five minutes and that the corner was empty before Miller pointed the gun and officers fired 80 to 85 rounds.