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O'Reilly Auto Parts employee charged with 2nd-degree murder posts $125K bond, leaves WyCo Detention Center

Carl Ryan Kemppainen
Posted at 9:06 AM, Sep 24, 2023
and last updated 2023-09-24 14:17:11-04

KANSAS CITY, Mo. — An O'Reilly Auto Parts employee charged with second-degree murder in the killing of 23-year-old Diamond Steen, of Kansas City, Missouri, left the Wyandotte County Detention Center after posting a $125,000 bond.

Carl Ryan Kemppainen, 39, is accused of unlawfully, unintentionally and 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 shared in a statement Friday.

The killing took place Tuesday evening around 6:20 p.m. outside O'Reilly Auto Parts in the 4700 block of Parallel Parkway in Kansas City, Kansas.

The Kansas City, Kansas, Police Department says Steen and another individual allegedly entered the store and attempted to shoplift, leading to an altercation with Kemppainen, several other employees and non-employees.

Steen died at the scene.

"The reasoning by which police were called out were brought to my attention; part of that is still being investigated," Wyandotte County Prosecuting Attorney Mark Dupree said Thursday. "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."

The other alleged shoplifter was taken to an area hospital with minor injuries.

Police noted that gun violence was not involved in the incident.

For jurisdictions that utilize the Greater Kansas City Crime Stoppers Tips Hotline, anonymous tips can be made by calling 816-474-TIPS (8477), submitting the tip online or through the free mobile app at Tips leading to an arrest made through the Tips Hotline may be eligible for up to a $25,000 reward.

Annual homicide details and data for the Kansas City area are available through the KSHB 41 News Homicide Tracker, which was launched in 2015. Read the KSHB 41 News Mug Shot Policy.