(INSIDE EDITION) --A motorist who allegedly fatally shot a 3-year-old boy while he was out Christmas shopping with his grandmother has turned himself over to authorities.
Gary Holmes, 33, surrendered to police in Little Rock, Arkansas, on Thursday, five days after he allegedly shot Acen King during a road rage incident.
Holmes' girlfriend told authorities that the boy's grandmother, Kim King-Macon, was following their car too closely, according to a probable cause affidavit seen by Arkansas Online.
Holmes pulled over and allowed the woman's car to go past him, the affidavit said. When she reached a stop sign, she waited for "a few minutes" without driving off and Holmes honked, according to the affidavit. He then got out of his vehicle and allegedly fired a semi-automatic pistol.
When he got back in the car, he said, "That's what you get for following me around," according to the affidavit.
King-Macon was unaware that her grandson had been hit and continued driving for 10 miles to a J. C. Penney. When she stopped in the parking lot, she found the boy had a gunshot wound to his neck.
"My [grandson’s] been shot!” King-Macon could be heard screaming in a 911 recording.
"I was at the stop sign and the guy blew the horn at me and I blew it back, and he shot but I thought he shot in air, but he shot at the car," she told the dispatcher.
She reportedly attempted to give the boy CPR in the parking lot until emergency services arrived. Acen was rushed to the hospital, where he died.
Both King-Macon and another 1-year-old was in the car at the time unharmed.
After Acen's death, authorities put out a $40,000 reward for information leading to the gunman's arrest.
Holmes turned himself in after U.S. Marshals and Little Rock police worked with his family to get him to surrender.
He was booked into the Pulaski County Jail on one count of capital murder and two counts of carrying out a terroristic act. He will be arraigned Friday.