Washington, DC…A Hamilton County, Ohio, man was sentenced to prison today for violating the Clean Air Act through an aftermarket scheme to disable the emissions control systems of diesel trucks.

Davis Owens, 34, of Cleves, was sentenced to serve 30 days in prison, seven months of home confinement and one year of supervised release. He had previously pleaded guilty to one count of aiding and abetting the tampering of a monitoring device required under the Clean Air Act.

According to court documents, Owens was the co-owner of Holderdown Performance and owner of Cincy Diesel Performance. In 2020, Owens entered a Consent Agreement and Final Order (CAFO) with the Environmental Protection Agency (EPA) regarding allegations that he and Holderdown had knowingly worked to bypass or “defeat” components that controlled emissions on heavy duty diesel truck engines. Research has shown that bypassing a vehicle’s emissions components can increase particulate matter 40 times, nitrogen oxides 310 times, carbon monoxide 120 times and non-methane hydrocarbons 1,100 times.

Owens paid a $7,500 civil penalty as part of the CAFO and agreed that neither he nor Cincy Diesel Performance would manufacture, sell or install defeat devices. Investigation revealed that Owens and Cincy Diesel Performance continued to sell and install defeat devices as well as emissions deleting computer software until February 2022.

Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division and U.S. Attorney Kenneth L. Parker for the Southern District of Ohio made the announcement.

The EPA’s Criminal Enforcement Division and the Ohio Attorney General’s Bureau of Criminal Investigations investigated the case.

Senior Trial Attorney Adam Cullman of the Environment and Natural Resources Division’s Environmental Crimes Section prosecuted the case.