Carol Gray, dressed in all black and wearing sunglasses, broke down as she demanded justice and questioned the NYPD's claim that her son, who had several previous arrests, had pointed a loaded .38-caliber revolver at the officers before they fired 11 shots at him.
"He is not the public’s angel, but he’s my angel and he’s my baby and he was slaughtered and I want to know why," Gray said, choking back sobs.
"Even after the first shot, why the second bullet?" Gray continued. "Why the third bullet? Why the fourth bullet? Why?"
Sitting alongside City Councilman Charles Barron and Kenneth Montgomery, the family's lawyer, Gray told reporters that her son was a "regular teenager" who sometimes got in trouble but was not in a gang, usually respected his 10 p.m. curfew and was terrified of cops.
Kimani Gray had previous arrests for breaking into a car, possession of stolen property, grand larceny and rioting, and police sources said he was a Bloods gang member.
But his mother said her son had only been arrested for "minor infractions" such as "joyriding," and denied that he was part of a gang.
"He's not named Kimani Blood, or Kimani Gang — he's named Kimani Gray," Carol Gray said. "He's my baby, and that’s how I want to remember him."
Last Saturday night, Kimani Gray was standing with a group of friends outside a sweet 16 party at his best friend's home in East Flatbush when the two officers approached in an unmarked car, according to police and relatives.
NYPD officials said Kimani Gray was behaving suspiciously and adjusting his waistband, so the officers confronted him and then shot him when he pointed the loaded weapon at them.
But eyewitnesses have reportedly disputed police accounts that Kimani Gray was armed, leading supporters to demand that prosecutors get to the bottom of the confusion.
"I want a thorough investigation — a legal, thorough investigation," Gray said. "No smokescreen, no sugarcoating."
At a separate event on Thursday, Gerard Gray, Kimani Gray's father, said quietly, "I just want the truth."
Several witnesses told DNAinfo.com New York Kimani Gray had his hands up and was lowering himself to the ground when the officers shot him, an account his mother repeated on Thursday.
"Why was Kimani begging for his life?" she said. "Why was Kimani saying, 'You got me, I’m down, don’t shoot me no more?'"
Montgomery, who is representing the Gray family, said the only way to get to the bottom of what happened is for the Brooklyn District Attorney's office to investigate.
At a separate press event, Mayor Michael Bloomberg promised Thursday to "conduct a full and fair investigation."
Bloomberg said he had not yet spoken to Kimani Gray's parents but planned to do so.
Coping with her son's death is even harder for Carol Gray because her oldest son was killed in a car crash just two years ago.
"Now I have to place my younger boy in the same hole that his brother is in," said Gray, who broke down as she described picking out Kimani Gray's casket on Thursday.
Gray also spoke out against the violent demonstrations that have broken out in East Flatbush this week in response to her son's death.
"I don’t condone any riots, any looting, any shooting, anything against police officers," Gray said. "Two police officers shot down Kimani. I only want justice for [those] two police officers to be off the street before they hurt other young kids."
Bloomberg said Thursday that police will have a strong presence in East Flatbush to prevent further violence.
"I understand there's anger in the community, but the place to get answers is not through violence or law-breaking," Bloomberg told reporters. "We cannot tolerate that and we will not tolerate that."
Gray said she's still having trouble believing her son is gone. She's accustomed to waiting up at night to hear the bell that means her son has come home.
"But for the past couple days, I haven’t heard that bell," she said. "And I’m still waiting."
With reporting by Jill Colvin, Ben Fractenberg and Aidan Gardiner