The children’s father told local reporters that the child might have mistaken the gun, which belongs to a relative, for a toy.
Failure to inspect a prop gun would be a major breach in safety protocol.
The projectile was one of 500 rounds of ammunition found on the set of the Alec Baldwin film, though it's unclear how many were live.
"He did not maintain a safe working environment," said a prop maker who worked with Dave Halls in 2019.
Reports of trouble brewing over safety concerns have emerged in the days following the cinematographer's death on the set of "Rust."
The prop gun had several misfires in recent days, a source told the Los Angeles Times, raising questions about safety procedures on set.
A friend brought a gun over to the house, according to police in Chula Vista, California.
“Words cannot express the devastation and heartache that our team is feeling right now upon learning of the tragic death of our teammate and brother, Ty Jordan,” Utes head coach Kyle Whittingham said.
Richard Dennis, 62, will not face charges for the shooting that's being called a "horrible accident."
The victim, who remains in the hospital, didn't have a license to carry a handgun in Indiana, police said.