A 4-year-old boy was critically wounded after he found a .25-caliber pistol earlier this week and accidentally shot himself outside a Summerville home, according to an incident report released Wednesday.

The boy was taken to Medical University Hospital, where he remained Wednesday, according to Summerville Police Department Capt. Jon Rogers.

Rogers said investigators were still trying to determine whether any criminal charges should be filed.

The police report did not name the child.

The boy's 75-year-old grandmother, Margaret G. Wilson called 911 around 4:40 p.m. Monday to report the shooting at 811 W. Richardson Ave.

She later told the police that she had just returned home with the boy and was putting away groceries when she heard the lone gunshot.

No one else was home at the time, Rogers said. The boy, who lives in North Charleston, was visiting.

Wilson rushed outside and found the boy lying in the front yard. He was bleeding from a wound in his head, the report stated.

The pistol rested nearby.

"I don't know where he got a gun from," she told the 911 dispatcher. "Somebody, please come. Come quick."

The boy wasn't breathing, the woman told the dispatcher. His eyes were closed.

"He's just 4 years old," Wilson said. "I don't know whether he's alive or what."

Paramedics, firefighters and a deputy from the Dorchester County Sheriff's Office were already there when Summerville police officers showed up.

By then, the .25-caliber Taurus pistol had been placed on the dining room table, and the boy was lying on the floor.

A helicopter later flew him to the Charleston hospital.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.