Police arrested Charles Edward Turner, 51, in Saturday’s incident at 2 p.m., police say. He is facing multiple charges, including assassination charges and four charges of aggravated assault, reports show. He is being held in Allegheny County Jail.
The boy was taken to hospital in critical condition and was upgraded to a stable, the KDKA reported, citing the criminal complaint.
Police say they do not know of any relationship between the boy and Turner, KDKA reported.
CNN has not been able to identify a lawyer for Turner.
Two McDonald’s employees stepped in to help the boy, Cara Cruz, deputy information officer for the Pittsburgh Public Safety Department, told KDKA.
“He was with his family, he was in line, they just stepped in for one thing,” Cruz told KDKA.
The motive remains unclear and the investigation is ongoing, police say.
Detectives from the Major Crimes and Crime Scene units watch the scene, analyze video evidence and speak to eyewitnesses, the Pittsburgh Public Safety Department said.