SUPERIOR, Mont. — An Army veteran pleaded not guilty Wednesday to assaulting a 13-year-old boy who the suspect said refused to remove his hat during the national anthem at a rodeo in Montana.

Attorney Lance Jasper has told the Missoulian that defendant Curt Brockway, who suffered a traumatic brain injury from an automobile crash while he was stationed at Fort Lewis, Washington, believed he was doing what President Donald Trump wanted him to do.

“His commander in chief is telling people that if they kneel, they should be fired, or if they burn a flag, they should be punished,” Jasper said. “He certainly didn’t understand it was a crime.”

Jasper is seeking a mental health evaluation for Brockway, 39, of Superior, Montana.

Brockway told investigators the boy cursed at him when he asked him to remove his hat at the Aug. 3 rodeo.

Witnesses have said Brockway picked the boy up by his neck and slammed him to the ground. The boy suffered a skull fracture, court records said.

The interaction drew national attention and Jasper said he received death threats along with Brockway and his family. Security was tight for Wednesday’s hearing before District Judge John Larson, with 16 law enforcement officers present.

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Brockway remains free without bond. His next hearing is Oct. 23.

Larson reinstated Brockway’s probation from a conviction for assault with a weapon in 2010.

Jasper did not immediately return a phone call Wednesday from The Associated Press seeking further comment.