A suspect has been arrested in the fatal shooting of a 12-year-old Long Island girl, who was hit by a stray bullet in her living room last fall, cops said.

Jakwan Keller, 20, was arrested Sunday for allegedly firing the errant shot that killed little Dejah Joyner in Hempstead on Oct. 16.

Keller, also of Hempstead, was held Sunday at the Nassau County police headquarters in Mineola. Keller is set to be arraigned on Monday.