NEW YORK -- A grand jury will not indict a New York City teen boy accused of killing his mother's abusive ex-boyfriend, court officials said Monday.

WTVR reports that 18-year-old Luis Moux was charged with manslaughter in August after allegedly choking his mom's ex-boyfriend to death. Police say the teen reportedly saw Stanley Washington beating his mother inside their apartment.

Police say the ex-boyfriend showed up at the apartment to talk to the mother during the early morning hours, and that's when he allegedly attacked her.

Moux heard what was happening, ran out of his bedroom, and allegedly put Washington in a choke hold, killing him, according to police.

Investigators say the mom briefly passed out, and woke up to find her son standing over her ex-boyfriend.

Police say Washington had 26 prior arrests - two of them were for domestic violence instances involving Moux's mother.