MARTINEZ, Ga. (WJBF) – A teenager is being charged with murder after a late night shooting in Martinez.

It happened just before 11:30 pm Monday night at a home on Tailboard Court near Stagecoach Way.

Police say 16-year-old Sonny Kristopher Kim killed his sister, 23-year-old Ashley Kim, by shooting her multiple times.

Ashley Kim died at the scene.

Sonny Kim is now facing murder charges.

Investigators say Sonny planned to kill his whole family and then himself.

Major Steve Morris says he planned on shooting his stepfather, mother, sister and himself in that order.

He shot his sister first because she was on the couch.

After his stepfather heard shots, he ran out and stopped him, while he was attempting to reload, before he could hurt anyone else.

Morris says Kim was an intelligent teen. He had already graduated high school and was taking college courses.

When investigators asked Kim why he planned to kill his family and then himself, he responded that he didn’t know.