SACRAMENTO, Calif. - The last defendant in the biggest criminal fraud scheme in the history of the Eastern District of California was sentenced today, U.S. Attorney Eric Grant announced.

Ronald J. Roach, 59, of Walnut Creek, was sentenced by U.S. District Judge Dale A. Drozd to 66 months in prison. Roach and co-defendant Joseph Bayliss were the first DC Solar defendants to plead guilty on Oct. 22, 2019.

"Today's sentencing marks the final chapter in an extensive fraud that caused significant loss. This outcome reflects years of careful, methodical investigative work and a prosecution built on meticulous attention to detail," said U.S. Attorney Grant. "None of the eight defendants went to trial, but each ultimately accepted responsibility and pleaded guilty. Our office remains committed to holding accountable those who exploit others for personal gain. We will continue to pursue justice with diligence and integrity."

"As the company's accountant, Ronald Roach concealed the truth from investors for years, enabling DC Solar to operate on fabricated financials," said FBI Sacramento Special Agent in Charge Sid Patel. "This fraud permeated nearly every level of the company's criminal operations. Today's sentencing reflects the tireless efforts of FBI Sacramento and our partners at IRS-CI, FDIC-OIG, and the U.S. Attorney's Office, who spent years methodically dismantling one of the largest fraud schemes in the Eastern District of California."

"The sentencing of Ronald Roach underscores the unwavering pursuit of accountability in this far-reaching fraud scheme," said Linda Nguyen, Special Agent in Charge of IRS Criminal Investigation, Oakland Field Office. "The DC Solar case revealed a deliberate and sweeping effort to abuse federal tax incentives and deceive investors on an extraordinary scale. IRS-CI, together with our law enforcement partners, remain firmly committed to ensuring every individual responsible is brought to justice."

"Mr. Roach ignored his responsibilities as a certified public accountant, conspiring with his co-defendants to defraud individuals, financial institutions, and the U.S. Government," said Special Agent in Charge Ryan Korner from the Federal Deposit Insurance Corporation Office of Inspector General (FDIC OIG). "This case highlights that no matter how complicated the fraud, FDIC OIG and our law enforcement partners will join forces to unravel the scheme, hold the perpetrators accountable, and bring justice to victims."

According to court documents, Roach played a central role in the DC Solar fraud. As DC Solar's accountant, he lied to investors and worked with others at the company to conceal the lack of third-party lease revenue. Between 2011 and 2018, DC Solar manufactured mobile solar generators that were mounted on trailers and claimed that they were used to provide emergency power to cellphone towers and lighting at sporting and other events. A significant incentive for investors was generous federal tax credits due to the solar nature of the generators.

A key part of the fraud was that investors would never actually take possession of the generators. Instead, DC Solar typically leased those generators back from the investors and claimed to sublease them to third parties to generate revenue. In reality there was very little actual third-party rental demand for the generators, but the co-conspirators at DC Solar continued to claim that the rental market for the generators was robust. They took new investor money to pay obligations to existing investors.

Between March 2011 and Dec. 18, 2018, investors invested approximately $759.4 million, and several financial institutions and other investors transferred $152.7 million to DC Solar as part of related transactions for the purchase and lease of generators. In total, DC Solar closed transactions with investors that contributed more than $912 million to purchase generators. Those transactions were purported to involve approximately 17,000 generators, at approximately $2.5 billion in value.

During the conspiracy, approximately 94% to 95% of the lease revenue on the books was actually intercompany transfers disguised as new investor money. In truth, third-party end-user demand for generators never exceeded 5% of the revenue that was claimed.

The FBI, IRS-CI, and the FDIC OIG conducted the investigation. Assistant U.S. Attorneys Audrey B. Hemesath and Nicholas M. Fogg prosecuted the case.

The status of the other seven defendants is as follows:

• Jeff Carpoff, 55, of Martinez, was sentenced on Nov. 9, 2021, to 30 years in prison and ordered to pay $790.6 million in restitution.
• Paulette Carpoff, 52, of Martinez, was sentenced on June 28, 2022, to 11 years and three months in prison.
• Joseph W. Bayliss, 50, of Martinez, was sentenced on Nov. 16, 2021, to three years in prison and ordered to pay $481.3 million in restitution.
• DC Solar CFO Robert A. Karmann, 59, of Clayton, was sentenced on April 12, 2022, to six years in prison and ordered to pay $624 million.
• Alan Hansen, 54, was sentenced on May 31, 2022, to 39 months in prison.
• Ryan Guidry, 49, of Pleasant Hill, was sentenced on Jan. 31, 2023, to six years and six months in prison and ordered to pay $619,415,950 in restitution.
• Ari J. Lauer, 61, of Lafayette, was sentenced on March 9, 2026, to 11 years and five months in prison. One week before trial, on Oct. 14, 2025, Lauer pleaded guilty to one count of conspiracy to commit wire and bank fraud, 12 counts of bank fraud, and 10 counts of wire fraud affecting a financial institution.