SALT LAKE CITY—The father of a 4-year-old boy who fired a gun at police told investigators the child had gotten ahold of the weapon before, according to police documents. The child stuck the gun out of a car window as police arrested his father, who had brandished his gun at McDonald’s workers over an incorrect order on Monday, police said. An officer spotted the gun and instinctively swiped it away, sending the shot into the side of the building, said Sgt. Melody Cutler with Unified Police of Greater Salt Lake. The officer also yelled “kid” to alert his fellow officers that the person with the weapon was a child. Both the boy and a 3-year-old sibling were taken into the care of child-welfare workers and will be interviewed as part of the investigation. Their father, a 27-year-old recent transplant from Georgia, is being held without bail on suspicion of felony …