Police arrested Charles Edward Turner, 51, on Saturday at 2 p.m. He faced several charges, including culpable homicide and four counts of aggravated assault. He is being held in the Allegheny County Jail.
The boy was brought to the hospital in a critical condition and was upgraded to stable, KDKA reported with reference to the criminal charge.
Police say they do not know of any relationship between the boy and Turner, reports KDKA.
CNN has not yet been able to identify a lawyer for Turner.
Two McDonald’s employees intervened to help the boy, Cara Cruz, deputy public information officer for the Pittsburgh Department of Public Safety, told KDKA.
“He was with his family, he was standing in line, they were only pulling for one quick thing,” Cruz told KDKA.
The motive remains unclear and the investigation continues, police said.
Detectives from the major crime and crime scene units are investigating the scene, analyzing video evidence and talking to eyewitnesses, the Department of Public Safety has published.