Witnesses to the shooting death of a 16-year-old Brooklyn teenager at the hands of New York City Police detectives have begun raising questions over authorities' account of the fatal encounter.

WNBC-TV reported on Monday that Kimani Gray was shot 11 times by the detectives. A 19-year-old man who was allegedly at the scene told the station the officials did not identify themselves as police before approaching them.

"They shot him," said the witness, who did not identify himself. "They didn't ask him no questions, no nothing, they just shot him."

But department spokesperson Paul J. Browne told the New York Times that Gray threatened the detectives.

"After the anti-crime sergeant and police officer told the suspect to show his hands, which was heard by witnesses, Gray produced a revolver and pointed it at the officers," Brown said.

Police also said Gray had been arrested four times before his encounter with the detectives, on charges including inciting a riot, grand larceny and possession of stolen property.

Gray's sister, Mahnefah Gray, told the newspaper she and other friends of Gray's never knew him to have a gun. She also said her brother would not have pointed one at the officers.

"He has common sense," she said.

Another witness, Camille Johnson, told WPIX-TV Gray was fleeing the scene when he was killed.

"He was running for his life, telling the cops, 'Stop,'" Johnson said. "They really are, seriously, walking around, shooting little kids."

Another witness, who said she lives across the street from the scene of Gray's death, said she saw him on the ground clutching his stomach while two men stood over him.

"He said, 'Please don't let me die,'" said the witness, who identified herself using only her first name, Vanessa. She added that one of the officers answered, "Stay down, or we'll shoot you again."

Gray was pronounced dead Saturday night at a local hospital. The two officers involved have been placed on paid administrative leave while the department investigates the incident.

Watch WNBC's report on the questions surrounding Gray's death, aired Monday, below.

View more videos at: http://nbcnewyork.com.

[h/t Think Progress]