Friends describe Ryan Carter as a man of unmatched kindness and immeasurable talent, with a heart as big as his smile. A motorcycle enthusiast, Carter also loved photography and spent his time shooting pictures of nature, wrestling and roller derby.

On Tuesday afternoon, Carter, 38, was killed while riding his motorcycle. Baton Rouge Police say an Alabama man driving an 18-wheeler repeatedly struck and then ran over Carter after he was thrown from his motorcycle on Florida Boulevard near North Eugene Street.

The truck driver, Howard Lyons, 61, was arrested and booked into East Baton Rouge Parish Prison on negligent homicide following the crash, which was witnessed by several Baton Rouge Police officers and an Alcohol Beverage Control officer already on scene responding to an earlier, unrelated incident.

According to the arrest report, officers were investigating an earlier crash in the 2500 block of Florida Boulevard at 4:34 p.m. Tuesday when they saw a black motorcycle traveling eastbound, followed by a red 18-wheel truck pulling a tanker trailer.

+3 Coroner contacted after motorcyclist struck by 18-wheeler on Florida Street, officials say Police are investigating a fatal crash involving an 18-wheeler that struck a motorcycle on Florida Street in Baton Rouge late Tuesday afternoon.

As Carter was passing the officers, police witnessed him yelling at the truck driver behind him. Lyons then drove forward and struck the motorcycle several times in the rear, the report says.

While an officer yelled for them to pull over to the side of the road, Lyons instead accelerated and struck the motorcycle in the rear again, the report says.

On impact, Carter was thrown from his vehicle and run over by "every tire on the passenger side of the truck," the report says. Carter was immediately killed.

Photos from the scene show the motorcycle wedged beneath the front bumper of the semi.

Lyons told police he has been driving trucks for over 40 years and did not see the motorcyclist at the time of the incident.

He said he thought he had hit a pothole and was accelerating to keep up with traffic, though a surveillance video shows the motorcycle was several vehicle-lengths in front of the 18-wheeler before the final crash, the report says.

According to a traffic court clerk in Cullman County, Alabama, where Lyons lives, he has incurred at least two traffic tickets in the last 20 years in the state of Alabama, one in 2001 for speeding at 78 mph in a 65 mph zone, and another in 2010 for a seat belt violation. Both tickets were paid, she said, and both tickets were issued in Colbert County, Alabama.

Friends took to social media Wednesday to mourn Carter, of Baton Rouge, and share stories about his life.

Stacy Sullivan, a friend of Carter’s, said he was a photographer who ran his own company, Spade Photo. She said his photography was all his own, from his equipment to his website.

“He loved taking photos, and it definitely showed in his work,” Sullivan said. “He loved his wife, his cats and his motorcycles, and he loved photographing all of those things as well.”

Sullivan, who is the president of Red Stick Roller Derby, said Carter began to volunteer his time with the league to take head shots of the team, in addition to shooting their games, when his wife joined as a skater.

Anna Lacy, president of Red Stick Junior, a roller derby league for girls ages 7-17, said Carter would also take head shots for the skaters in her league. He was great with kids, she said, and was always full of jokes and creativity.

"Even if the kids were nervous, he just had this attitude where they were instantly confident and comfortable around him," Lacy said.

She added that Carter loved animals and spent so much time photographing Mike the Tiger at its LSU enclosure that Mike would recognize him when he arrived with his camera.

"He would come right up to the glass and start rubbing his head on the glass like he was a house cat wanting scratches when Carter showed up," Lacy said.

Sullivan said Carter "was one of the most genuine people I'd ever met, and was always an absolute joy to have around."