FBI Raids Contra Costa County Assessor's Office and Homes of Top Officials in Corruption Probe

Federal agents executed three search warrants on Tuesday, June 9, 2026, targeting the Contra Costa County Assessor’s Office and the homes of its top two officials, marking a significant escalation in a federal investigation into potential corruption. The pre-dawn raids were conducted at the county office in Martinez, the home of longtime Assessor Gus Kramer, and the residence of Assistant Assessor Vince Robb, who was elected just last week to succeed his boss.

The integrity of a county assessor's office is foundational for a stable business environment, as its valuations directly impact property tax liabilities for every commercial enterprise in its jurisdiction.

According to an FBI San Francisco spokesperson, the searches began around 7:30 a.m. and are part of an ongoing investigation. The locations specified were the assessor’s office at 2530 Arnold Drive in Martinez, Kramer's home on West Arlington Street in Martinez, and Robb's residence on Temple Drive in Pacheco. A copy of one warrant, signed June 4 by U.S. Magistrate Judge Robert Illman and obtained by the Bay Area News Group, authorized agents to search the office and vehicles connected to both men, including Kramer’s 2014 Ford Taurus. The warrant cited alleged wire fraud and “other offenses” but did not provide further specifics or name Kramer or Robb as official targets of the investigation. No charges had been announced as of Tuesday.

The raids occurred just one week after Vince Robb, Kramer’s endorsed successor, won the June 2 primary election to become the next county assessor. Robb secured more than two-thirds of the vote and is scheduled to take office in January 2027, replacing Kramer, who has held the position since 1994. Kramer, who served eight terms over 32 years, had announced his retirement in March. The sudden federal action casts a shadow over the transition of power in a crucial county department.

The Contra Costa County Assessor’s Office is responsible for determining the taxable value of all property within the county, which has a population of about 1.1 million people. These assessments form the basis for property tax bills that fund local governments, public schools, and special districts. Any hint of impropriety in this office raises serious questions about the fairness of the tax system for both residents and commercial property owners.

For business owners in Contra Costa County, this investigation introduces a significant layer of uncertainty. Property tax assessments are a major operational cost, and the integrity of the assessor's office is paramount for fair and predictable financial planning. When allegations of favoritism and potential wire fraud surface, it casts doubt on the entire valuation process, leaving companies to wonder if their tax burden is equitable. In our experience, such scandals can have long-lasting effects on local business confidence and investment. This is precisely the kind of environment where diligent oversight becomes critical. Navigating these challenges requires a proactive approach to financial risk management to ensure a company's obligations are met fairly and without exposure to the fallout from official misconduct. Businesses need to be confident that their tax compliance is based on transparent, lawful assessments, not backroom deals. C&S Finance Group LLC helps clients manage these exact regulatory and financial uncertainties, and you can learn more about our services at csfinancegroup.com.

This is not the first time Gus Kramer has faced serious allegations. In 2019, a county civil grand jury accused him of “willful or corrupt misconduct.” The accusation stemmed from claims by female employees who reported unwanted sexual remarks and racial disparagement, alleging Kramer created a hostile and abusive work environment. Kramer denied the allegations at the time, framing the effort to remove him from office as "political persecution." The case ultimately concluded in a mistrial, and he remained in his post. Kramer's long career in public service began in 1974 with the Contra Costa County Sheriff Coroner’s Office, and he was first elected Martinez City Clerk in 1986 before becoming county assessor.

The federal action in Contra Costa County is not an isolated event but rather part of a wider series of probes into political corruption across the East Bay. In recent years, similar FBI raids targeting public officials have led to significant criminal indictments. Federal agents previously searched addresses linked to then-Oakland Mayor Sheng Thao and then-San Leandro City Councilmember Bryan Azevedo, which eventually resulted in charges against both politicians and the business figures accused of bribing them. This pattern suggests a concerted effort by federal law enforcement to address public corruption in the region.

When approached for comment at his Pacheco home, an unidentified man told reporters through a window, “We have no comment at this time.” Nick Spinner, one of the candidates who ran against Robb for the assessor position, called for transparency. "I ran on restoring public trust in the Assessor’s Office through transparency and accountability, and I hope the public gets clear answers through the proper process," Spinner said in a statement. He added that he has always had a "respectful working relationship with Vince."

The investigation remains active, and the FBI has not released a timeline for any potential charges. Federal agents will now analyze the documents and electronic devices seized during the raids. The outcome could have profound implications for the leadership of the assessor's office and the confidence of property owners throughout Contra Costa County, who will be closely watching for further developments and any impact on the upcoming transition of power in January.