Cody Harter had done tours in Iraq and Qatar, and as a member of the Missouri Air National Guard, he helped with hurricane relief in Houston and Puerto Rico.
But on Saturday evening, the engaged man was fatally stabbed in what police say was a road rage incident with an unknown suspect.
"He brought us great joy," said his mother, Kerrie Harter. "He knew great joy. He brought us love... he was not just a number, he was a person. He was my love... and now we know pain and loss."
Police in the Kansas City suburb of Lee's Summit are searching for a suspect and are asking any of the hundreds of people that drove by the scene to call with information.
Police said witnesses saw another vehicle stopped in front of Harter's truck and saw the guardsman, 23, arguing with someone outside their vehicles. Police said they believe the motorist suffered a single stab wound to the chest during the altercation, stumbled back into the roadway and then collapsed in the inner median.
His truck was found not far away, on the shoulder of the highway.
His mother said Harter had a lawn-care business and had one semester left until he graduated with an engineering technology degree. He also was a novice dirt bike rider and spent his weekends at the track, she said.
"He loved everyone, he would help anybody," she said.