A 17-year-old boy allegedly found a gun in the woods and later used it to shoot and kill a 13-year-old Wednesday night, according to DeKalb County police.

Investigators believe Aaron Harcum, 17, shot 13-year-old Marcus Lewis in the face while the two were in the garage of a Lithonia home, Major Steve Fore said.

Harcum ran to a neighbor’s house for help. Marcus was taken to Grady Memorial Hospital, where he later died, police said.

Harcum was arrested early Thursday morning and charged with involuntary manslaughter. Harcum’s bond was set at $25,000 at his first court appearance Thursday night.

It was not known Thursday who owned the gun.

“We will track the weapon to find out where it was purchased, where it originally came from,” Fore said.

Marcus attended Salem Middle School, loved basketball and planned to run track this spring, his mother, Sonia Wheeler told Channel 2 Action News. Marcus had gone to a friend’s home on Idlewood Park to lift weights with a friend when Harcum arrived with the gun, Wheeler said.

Wheeler said she didn’t know Harcum and isn’t sure why he would have been hanging around younger boys. Marcus was her only child, Wheeler said.

“He kept me strong,” Wheeler said. “He was my one child, the only child I have. I have him in my memory but not here physically.”

An online fundraising page was created to assist the family with funeral costs.