San Juan Capistrano Man Agrees to Plead Guilty to Federal Charges for Running Illegal Sports-Betting Business and Cheating on Taxes

LOS ANGELES – An Orange County man has agreed to plead guilty to federal criminal charges for running an illegal gambling business that took in unlawful sports bets, including from then-current and former professional athletes as well as a former Major League Baseball (MLB) Japanese-language interpreter currently facing prison time.

Mathew R. Bowyer, 49, of San Juan Capistrano, has agreed to plead guilty to a three-count information charging him with operating an unlawful gambling business, money laundering, and subscribing to a false tax return.

Bowyer is expected to plead guilty to the charges on August 9.

According to his plea agreement, Bowyer operated an unlicensed and illegal bookmaking business that focused on sports betting and violated a California law that prohibits bookmaking. Bowyer’s gambling business remained in operation for at least five years until October 2023 and at times had more than 700 bettors.

He operated this business out of various locations in Los Angeles and Orange counties as well as in Las Vegas. Bowyer also employed agents and sub-agents – including casino hosts – who worked for his illegal gambling business who were paid a portion of the losses that bettors incurred and paid. His unlawful business used several Costa Rica-based websites and a call center so agents and customers could place and track bets. At times, Bowyer operated his illegal business while gambling at a casino – identified in court documents as “Casino A” – and sometimes paid his agents commission in Casino A chips.

One of Bowyer’s clients was Ippei Mizuhara, who pleaded guilty on June 4 to one count of bank fraud and one count of subscribing to a false tax return. Mizuhara was the Japanese-language interpreter and de facto manager of MLB superstar Shohei Ohtani. Mizuhara admitted to stealing nearly $17 million from Ohtani to pay off gambling debts and failing to pay tax on his gambling income. Law enforcement considers Ohtani a victim. Mizuhara’s sentencing hearing is scheduled for October 25.

From September 2021 to January 2024, Mizuhara placed at least 19,000 bets with Bowyer’s illegal gambling business through one of the betting websites Bowyer used for it. During this period, Mizuhara had total winning bets of at least $142,256,769, and total losing bets of at least $182,935,206, leaving Mizuhara owing approximately $40,678,436. On a regular basis during this period, Bowyer would increase Mizuhara’s betting limits.

From February 2022 to January 2024, Bowyer directed Mizuhara to make payments of at least $16.25 million to Bowyer-controlled bank accounts, all of which were proceeds of Bowyer’s illegal gambling business. Of these illegal proceeds, Bowyer transferred or directed the transfer of least $9.3 million to a casino in the form of wire transfers as payment for markers for Bowyer and his associates.

Other Bowyer gambling business customers included “Individual B,” a professional baseball player for a Southern California-based baseball club, and “Individual C,” a former minor-league baseball player.

Bowyer admitted in his plea agreement to knowingly and willfully falsely reporting his taxable income to the IRS on his tax return for the year 2022. On that year’s tax return, Bowyer reported $607,897 in total income. His unreported income for that year was $4,030,938, which was income from his illegal gambling business, including $3.8 million in wire transfers into one of his bank accounts, which he did not declare on his tax return. As a result of the false information Bowyer provided, he owes additional taxes of $1,613,280 for the tax year 2022, not including interest and penalties.

Upon pleading guilty, Bowyer will face a statutory maximum sentence of 10 years in federal prison on the money laundering count, up to five years in federal prison for the unlawful gambling business count, and up to three years in federal prison for the false tax return count.

As part of his plea agreement, Bowyer will forfeit $257,923 in U.S. currency and $14,830 in casino chips seized by law enforcement in October 2023. He also has agreed to fully cooperate with federal prosecutors and investigators.

IRS Criminal Investigation and Homeland Security Investigations are investigating this matter.

Special Assistant United States Attorney Rachel N. Agress and Assistant United States Attorney Dominique Caamano of the Environmental Crimes and Consumer Protection Section are prosecuting this case.