NewsKansas City Public Safety


O'Reilly Auto Parts employee charged with second-degree murder in KCMO man's death

Carl Ryan Kemppainen
Posted at 6:24 PM, Sep 21, 2023
and last updated 2023-09-26 07:08:15-04

KANSAS CITY, Kan. — An O'Reilly Auto Parts employee is accused of killing a man during an altercation that unfolded on Tuesday evening at the auto parts store in Kansas City, Kansas.

Carl Ryan Kemppainen is charged with second-degree murder in the death of Diamond Steen, Wyandotte County Prosecuting Attorney Mark Dupree said Thursday.

Kemppainen, 39, is accused of unlawfully and unintentionally, but recklessly, killing Steen.

"O’Reilly Auto Parts is deeply disturbed by the events, death and injuries that occurred at our store in Kansas City, Kansas. We are cooperating fully with the police investigation," the company said in a statement Friday morning.

The killing unfolded at the auto parts store located in the 4700 block of Parallel Parkway about 6 p.m. on Tuesday evening.

Officers located Steen unresponsive, and despite CPR efforts, he died at the scene. An autopsy revealed Steen's cause of death of was strangulation.

The Kansas City, Kansas, Police Department said the altercation stemmed from a shoplifting incident.

Police said Steen and another person allegedly walked into the store on the evening of the killing and began shoplifting.

Kemppainen, along with several other employees and non-employees, confronted Steen and the other alleged shoplifter outside of the store.

Dupree weighed in on whether the alleged shoplifting by Steen could've impacted the ability to file charges in his murder.

"The reasoning by which police were called out were brought to my attention; part of that is still being investigated," Dupree said. "If there was a potential crime that was being alleged, we do know that in this country, you still have to go to the court and someone's life cannot be taken."

Dupree said there were three other individuals involved and said additional charges could be filed.

Kemppainen is being held at Wyandotte County jail on a $125,000 bond.