Dauphin County Man Charged With Violations of Clean Air Act and Conspiring to Defraud the United States and Violate the Clean Air Act

HARRISBURG - The United States Attorney’s Office for the Middle District of Pennsylvania announced that Ryan Spencer, age 33, of Harrisburg, PA, was charged by criminal information on April 4, 2025, for conspiracy to impede the lawful functions of the Environmental Protection Agency (EPA) and to violate the Clean Air Act, and individual violations of the Clean Air Act.

According to Acting United States Attorney John C. Gurganus, between 2013 and March 12, 2024, Spencer, a Service Manager at Pro Diesel Werks, LLC, doing business as Pro Diesel Werks, along with Pro Diesel Werks owner Roy Ladell Weaver and other co-conspirators, disabled the hardware emissions control systems on the diesel vehicles of Pro Diesel Werks customers (a practice referred to as a “delete” or “deleting”), defeating the systems’ ability to reduce pollutant gases and particulate matter being emitted to the atmosphere. The information further alleges that Spencer and his co-conspirators also tampered with the emissions diagnostic systems on the vehicles to prevent the diagnostic system software from monitoring the emission control system hardware deletes (a practice referred to as a ‘tune” or “tuning).

On February 19, 2025, a federal grand jury indicted Weaver and Pro Diesel Werks for conspiracy to impede the lawful functions of the EPA and to violate the Clean Air Act, and individual violations of the Clean Air Act. 

The case was investigated by the EPA’s Criminal Investigations Division. Assistant U.S. Attorney David C. Williams, Environmental Crimes Section Trial Attorney Ronald A. Sarachan, and Environmental Crimes Section Senior Trial Attorney Richard J. Powers are prosecuting the case.

The maximum total penalty under federal law for these offenses is seven years of imprisonment, a term of supervised release following imprisonment, and a fine. A sentence following a finding of guilt is imposed by the Judge after consideration of the applicable federal sentencing statutes and the Federal Sentencing Guidelines.

Indictments and Criminal Informations are only allegations. All persons charged are presumed to be innocent unless and until found guilty in court.

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