A 12-year-old Long Island girl who was shot in the head Friday by a stray bullet died Saturday night.

Cops announced the death on Sunday morning, Newsday reported.

Dejah Joyner was struck in the brain when a bullet was fired into her Hempstead living room around 5 p.m. on Friday. Detectives are investigating the possibility that it was a gang-related incident. There have been no arrests, but police have offered a $75,000 reward as they search for the shooter.

“We cannot sit idly by as 12-year-old children are gunned down in their own living rooms”

- Madeline Singas, acting Nassau district attorney

Nassau County Police Commissioner Thomas Krumpter told Newsday the shooting was a “heinous criminal act…committed by a despicable human being.”

Witnesses reported seeing an older-model dark green or black Nissan speeding away moments after Joyner was hit.

“We cannot sit idly by as 12-year-old children are gunned down in their own living rooms,” Acting Nassau District Attorney Madeline Singas said. “This person…will pay for what he did to that 12-year-old.”

Joyner was described to Newsday by friends and relatives as a friendly girl with an infectious laugh. She was a girl scout who wanted to join the cheerleading squad and become a dancer.

“She was a happy little girl,” cousin Jade Floyd said. “We used to have so much fun. She would sleep over here. I’d sleep over there. We’d play together, listen to music and sing. We talked about everything.”