State police are investigating the circumstances of a weekend shooting that left a 3-year-old boy injured at a Butler home.

The child was injured Saturday night when he accidentally fired a gun while visiting his grandparents at their home on McKinley Avenue, authorities said.

The boy reportedly suffered powder burns on his face, which were not considered serious. He was treated at a Pittsburgh hospital and released.

The shooting happened at the house of Francis “Jack” and Carla Plaisted about 8:15 p.m.

State police are handling the investigation at the request of city police, who didn’t want to give the appearance of impropriety since Jack Plaisted served 32 years with the Butler Police Department before retiring in 2007.

“It’s an ongoing investigation and we’re trying to figure out what happened and if there’s any criminal culpability,” said state police Cpl. Daniel Herr.

He said it was premature to speculate if any charges would be filed.

Authorities said Carla Plaisted was there when the gun went off. Jack Plaisted was not at home. The gun, a .38-caliber revolver, belonged to the boy’s grandfather, authorities said.

The child found it while playing in the living room, Herr said. The gun was in the arm rest compartment of a recliner.

City police responded to the initial call but would not discuss any findings.

Butler Fire Chief Nick Ban confirmed that his department responded to the house for a “medical call” but he declined further comment.

Butler Ambulance Service took the boy to Butler Memorial Hospital. He was later taken to Children’s Hospital for additional treatment before being released.

Butler police on Monday contacted the Butler County District Attorney’s Office to determine if a different agency should investigate the shooting due to their familiarity with Jack Plaisted.

District Attorney Richard Goldinger said he was told that Butler police had spoken to one of his assistants following their call to the home.

“It’s up to (Butler police) to decide if they can do a fair, thorough and unprejudiced investigation,” Goldinger said Monday. “But my suggestion was for city police to call state police.”

Goldinger agreed with Herr that it was too early to say if charges would be brought.

“We don’t even know if there’s a crime here,” he said.

“Anytime there’s a child and a gun involved, it’s concerning,” Goldinger said. “I also understand that accidents can happen. But just because a gun is involved doesn’t mean there’s a crime.”

“Thankfully, the child was not seriously hurt. It could have been a lot worse.”

Jack Plaisted declined to comment Wednesday. He acknowledged he was consulting with a Butler attorney, who was not immediately retained.