NEW YORK - An unarmed, mentally disturbed teenager could be heard cursing and yelling, “I've got a gun!” during a frantic 911 call made by his exasperated mother before police arrived and killed him with a 20-bullet barrage, according to a tape of the call released Tuesday.

The mother cautioned police before the shooting that she didn't think her 18-year-old son, Khiel Coppin, really had a gun, and one wasn't recovered. But police officials insisted Coppin gave five officers no choice but to open fire after he suddenly charged them outside his mother's home with a black object in his hand; the object turned out to be a hairbrush.

Police Commissioner Raymond Kelly said the teenager pointed the brush at officers “as if he were aiming a gun” and repeatedly ignored orders to “stop, show his hands and get on the ground.” He said officers reasonably believed the victim was about to use deadly force and their response appeared to be within police department guidelines.

Coppin was brandishing a pair of knives when officers first arrived and taunted them by saying, “Come get me. I have a gun. Let's do this,” Kelly added.

The family of the victim denounced the police department for ruling too quickly that the officers were justified in their response.

“Nobody but Houdini himself could have decided that in 24 hours,” family attorney Paul Wooten said.

The victim's brother complained his background had been distorted by the media.

“He is a human being,” said Joel Coppin. “What we want is simply justice. ... We don't want headlines. We want justice for Khiel so every young black man in the city'll never go through this again.”

Police said two of the shooters were Hispanic and three were white.

The 17-minute episode began at about 7 p.m. Monday, when officers arrived at the Brooklyn home in response to a report of a dispute involving a gun. The mother had summoned a psychiatric intervention team earlier in the day, claiming her son was suicidal, but he took off before the team arrived, Kelly said.

According to the 911 call, while the emergency operator took down the address in Bedford-Stuyvesant, a male voice was overheard in the background saying, “I got a gun, and I'm gonna shoot you,” and, “I've got a (expletive) gun!”

The mother, Denise Owens, told the operator, “This ... you know ... this kid is a problem. You can even hear him?”

The operator: “Who is that?”

The mother: “That's supposed to be my son!”

When a 911 operator called back about five minutes later to ask Owens for a description of her son and the weapon, she told the operator, “He does not have a firearm,” a second transcript shows.

“I'm flipping out,” the mother added. “I can't handle this.”

When officers arrived at the home, they encountered Coppin inside with the knives. They backed off and ordered his mother and younger sister outside.

The teen began screaming from a first-floor window at his mother and officers before climbing out of the apartment window and crossing a sidewalk toward the officers while holding the hairbrush in his hand, police said.

The officers backed up and ordered him to stop, police said. When the teen refused and kept approaching them, they began shooting from a distance of 5 to 7 feet, police said.

Police said eight of the 20 bullets struck Coppin, who was pronounced dead at a hospital.

“This was a terrible tragedy for Khiel's family,” Kelly said.

Investigators also recovered notes they said were written by the victim with rambling observations about death and disillusion. One read: “Those closest 2 death iz closer 2 happiness.”

A neighbor, Bernice Sanders, said she looked out her window Monday night after hearing the police order someone to “Get down!” She also described seeing officers with their guns drawn, taking cover behind a car.

“The boy did not respond to them,” she said. “Next thing gunshots, ‘Boom, boom, boom.' The young boy is laying on the ground. They handcuffed him on his back.”

Asked whether the incident could be a case of “suicide by cop,” Kelly said, “That's certainly a distinct possibility.”

Patrolmen's Benevolent Association president Patrick Lynch was quick to come to the officers' defense.

“This is an unfortunate situation where the deceased convinced everyone involved - from family members to responding officers - that he was in possession of a gun,” Lynch said. “Tragically, he sought and succeeded in forcing a deadly confrontation with police.”

Police said the teen's mother had attempted to have him hospitalized earlier on Monday. They said the teen had a history of mental illness.