Two officers trained to deal with mental-health issues responded to 911 calls around noon and found Johnson moving in and out of the house breaking items, Vanore said.
The officers tried to resolve the situation, but Johnson continued to behave violently, Vanore said.
"The incident took some time," he said.
At some point, Johnson armed himself with several sticks and tried to set them on fire on a stove, and then attempted to attack the officers in his house, Vanore said.
An officer fired a Taser at Johnson, but it had no effect, Vanore said.
Johnson was then hit by a second Taser cartridge and collapsed, he said. Johnson received first aid at the scene and then was transported to Nazareth, in Northeast Philadelphia, where he died.
The cause of Johnson's death is under investigation, Vanore said.
He could not recall whether anyone had ever died in Philadelphia after being subdued with a Taser.
A man in front of the house declined to comment, saying the family was too upset. Two neighbors who did not want to give their names said Johnson was known to have mental problems.
The Police Department has expanded the use of Tasers in recent years. They were introduced as a way to subdue suspects without using a gun. Only officers who have received crisis-intervention training can use Tasers.
Philadelphia gained unwanted notoriety in May when police fired a Taser at a 17-year-old who ran onto to field at a Phillies home game.
The incident raised questions about the need for using the Taser when no one's life was in danger.
Amnesty International, which alleges that Tasers are being used excessively in situations that are not life-threatening, has reported that 351 people have died in the United States between June 2001 and August 2008 after being struck by a Taser.
Last year, a Philadelphia man died after being hit by a Taser fired by Pennsylvania State Police on I-95 in Tinicum Township, Delaware County.
Contact staff writer Robert Moran at 215-854-5983 or bmoran@phillynews.com.
Staff writer Allison Steele contributed to this article.