Dana Williamson served as Newsom's chief of staff from 2023 to 2024. She pled guilty to conspiracy, filing a false tax return, and lying to federal investigators.
Prosecutors say she helped divert $225,000 from a dormant campaign account belonging to Xavier Becerra.
Becerra is the former Secretary of Health and Human Services under president Biden. He's now the Democratic frontrunner in the race to replace Newsom as governor.
Williamson also admitted to falsely claiming personal expenses like luxury vacations and private jet travel as business expenses.
She and her co-defendants have agreed to pay $500,000 to the IRS, and $225,000 in restitution to Becerra
Williamson returns to court in July where she faces up to 30 years in prison.