Hasson George, known as Hass to his friends, died two weeks ago at a home in Jersey City.
The boys have the same father, and Hasson was found outside the home where the 14-year-old suspect lives with his mother. She is a corrections officer, and it was her weapon that fired the deadly shot.
Police believe the older child was playing with a gun when it went off, striking his brother in the chest.
The teeange suspect turned himself in Wednesday afternoon. He is officially charged with aggravted manslaughter, possession of a pistol for unlawful purposes and hindering the investigation.
The shooting happened inside the house on February 24, but Hasson's body was apparently dragged by someone to the sidewalk, where he was found by a neighbor.
The teen's attorney said that he received a call from the Hudson County Prosecutor's Office, which detailed the pending manslaughter charge.
Since he is being charged as a juvenile, the boy's identity is not being released.
His mother, who was home at the time of the shooting, is reportedly cooperating with investigators.
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