NEW ORLEANS (AP) — A man killed by police early New Year’s Day shot first when an unmarked car full of plainclothes officers pulled up next to his car, New Orleans Police Superintendent Warren Riley said Saturday.

‘‘I don’t know if he knew they were policemen when the first shot was fired. I don’t know,’’ Riley said during a news conference about the death of Adolph Grimes, 22, who has lived in Houston since Hurricane Katrina and was making a holiday visit.

Police displayed in the news conference a 9mm Glock 26, a magazine and 19 bullets which Riley said officers found on the body.

Asked whether Grimes fired more than once, he said, ‘‘We’ll release that when we have that.’’

Riley also disputed Coroner Frank Minyard’s statement Friday that Grimes was hit twice in the front torso and 12 times in the lower back and the backs of his legs. Riley said several rounds hit Grimes’ front, some hit his side under his arm, and some hit his back.

Nine narcotics officers involved in the incident — three women and six men — have been assigned to desk duty while the homicide division and the FBI investigate, he said. He said he would ‘‘happily’’ identify any found to have acted unprofessionally or illegally.

The group was investigating armed robberies in the area, with the women as holdup decoys and the men covering them.

‘‘They were all in plain clothes, as any tourist would be,’’ Riley said.

About 2:45 a.m., Riley said, a shooting was reported near a club in that area.

The officers answered. They were told that a white vehicle had left the area, and they saw a black vehicle drive away as they approached, Riley said.

The officers were in two unmarked cars; one group went to the club and the other looked for the black vehicle.

They found a parked black vehicle about four blocks from the club; as they pulled beside it, the man inside fired once. ‘‘The officers exited their vehicles; some remained in their vehicles and a gun battle or a gunfight ensued,’’ Riley said.

He said the man got out on the passenger side and pointed the gun at the officers ‘‘who then again returned fire.’’

Seven of the nine officers shot at him, Riley said. All fired more than once. He wouldn’t say how many bullets were fired.

‘‘We train our officers to fire when fired upon. We train them to fire more than one shot,’’ he said.

Asked if the officers identified themselves as they pulled up, he said, ‘‘That will have to come out as the investigation evolves.’’

Riley said he cannot say whether the officers overreacted. Because the cars were unmarked, they did not have incident cameras, Riley said.

The gun found on Grimes’ body had been fired at least once, the chief said.

Grimes’ family told The Times-Picayune that he was a cable installer in Houston and was in town for a New Year’s family visit.

Asked if he was worried about the family filing a complaint with the FBI, Riley said, ‘‘I think they should. Absolutely they should. … I’m sure that they do not believe that their son would have done anything like this.

���‘As a parent, I would certainly like to think that my kids wouldn’t do anything like that. They need to take every course that they feel is necessary to satisfy their concerns about this.’’