The New York Police Department on Tuesday released the first video of the shooting last week in which officers in Brooklyn shot and killed a mentally ill man who was holding part of a welding torch as if it were a gun and, the police said, pointing it at people on the street and then at arriving officers.

In the video, filmed from a security camera about half a block away, the officers and the man, Saheed Vassell, appear as small figures in the distance. Before the shooting, in the late afternoon on April 4 in the Crown Heights neighborhood, people gather at a bus stop, watching buses pass and peering down the street for another.

Then plainclothes officers in an unmarked sedan come into the picture. They drive down Utica Avenue, turn across traffic at Montgomery Street and crack their doors open. A marked police vehicle follows behind them.

About eight seconds later, before the officers get more than a couple steps from their car, the video shows them with their arms outstretched as if they are firing and people on the street flinch and then scatter. The officers are on one side of Montgomery Street, and Mr. Vassell is outside a market on the other side of the street. Mr. Vassell is seen dropping to the sidewalk.