9-year-old shot by stray bullet while walking on rural road

9-year-old Luke Knight, of Fulshear, Texas, was walking on a rural road with this grandfather and younger brother when he was hit in the leg by a bullet. From an article:

"You could hear it. It went POW! And I fell over and that was when it hit my bone," said Luke.
Luke spent the weekend at the hospital recovering from a bullet that was just millimeters away from killing him.
"The bone was completely split in half. The bullet had gone thru one side of his leg," said Luke's mother. "The bone was side by side and they knew it was near the artery."
Detectives are still trying to figure out where the bullet came from.