UPDATED at 11:30 a.m. with boy turning self in.

ST. LOUIS • A 13-year-old boy has turned himself into police after the shooting of another boy Wednesday in St. Louis' Walnut Park West neighborhood, police said.

The injured boy, also 13, was hospitalized in critical condition but was stable, Lt. Daniel Zarrick said at the scene.

He was shot in the chest just before 5 p.m. inside a home in the 5900 block of Lalite Avenue, near Riverview Boulevard, police said.

Police initially said the shooting appeared to be accidental, but Major John Hayden said afterward that police were conducting a criminal investigation to pursue all leads.

Hayden said three other juveniles were in the home at the time of the shooting. A 13-year-old boy was seen fleeing the scene after the shooting. Police called him a suspect, and he later turned himself in at the North Patrol Division. He was taken into juvenile custody.

Police had not recovered the gun. Several officers appeared to be searching an alley near the home shortly after the shooting.

The scene is near Northwest Academy of Law High School.

On Tuesday night, an 8-year-old boy was shot in the abdomen in the 4900 block of San Francisco Avenue, less than 2 miles away. Police believe he may have accidentally shot himself. He was stable but his medical condition was not available.