The federal investigation involves offices tied to outgoing Assessor Gus Kramer and Assistant Assessor Vince Robb.
MARTINEZ, CA — FBI agents served three federal search warrants Tuesday morning at the Contra Costa County assessor’s office and two East Bay homes as part of an ongoing investigation involving county tax officials.
The searches brought federal agents into an elected office that sets taxable property values across Contra Costa County, a Bay Area county of about 1.1 million people. No charges were announced Tuesday, and the FBI did not publicly name any target of the investigation. A partial warrant indicated agents were seeking evidence of wire fraud and other possible offenses.
Agents searched the assessor’s office in Martinez, outgoing County Assessor Gus Kramer’s home on West Arlington Street in Martinez and a residence on Temple Drive in Pacheco tied to Assistant Assessor Vince Robb. FBI San Francisco spokesperson Cameron Polan said the warrants were part of an ongoing investigation and said the bureau could not provide more detail. Agents left the assessor’s office around 1:30 p.m., but the office remained closed for much of the day. Kramer said he had not been told the specific reason for the searches. “I think this is a fishing expedition, based on rumor and innuendo,” Kramer said. “It’s drama and trauma. Totally uncalled for.”
The search put new attention on Kramer, who has held the elected assessor’s post since 1994 and did not seek another term. Robb, a longtime assistant assessor and close aide to Kramer, won election June 2 to succeed him, receiving more than two-thirds of the vote. The assessor’s office determines the taxable value of real estate and other property, which affects property tax bills and revenue for cities, schools, county services and special districts. Kramer said he did not know what agents took from his office. He said agents removed one document from his home. Robb did not immediately make a public statement Tuesday. It was not clear whether agents seized computers, phones, files or other records.
A warrant reviewed by local news outlets said investigators were searching for evidence of wire fraud and “other offenses.” The warrant was signed June 4 by U.S. Magistrate Judge Robert Illman. Federal officials did not release the supporting affidavit, which usually lays out the basis for a search. That left key questions unanswered, including what transaction, record or communication prompted the warrants. Kramer said he believed the investigation may have grown from complaints by former employees or from political conflict with the Contra Costa County Board of Supervisors. Board members declined to comment on the active investigation. One supervisor said the county was weighing legal options to protect the assessment process because Kramer is an elected official and cannot be placed on paid leave.
Kramer’s office has faced years of conflict. In 2019, a Contra Costa County civil grand jury accused him of willful or corrupt misconduct, alleging he created a hostile and abusive workplace after female employees reported unwanted sexual remarks and racial disparagement. Kramer denied wrongdoing, and the removal case ended in a mistrial. County supervisors publicly censured him that year. This year, the county settled a lawsuit by former supervising appraiser Andrea Albrecht, who alleged Kramer improperly lowered the assessed value of a Walnut Creek apartment complex and retaliated after she raised concerns. The property, Carmel Pines Apartments, was later sold for $10.3 million. Kramer has denied misconduct in past disputes and said Tuesday he has repeatedly been cleared after investigations.
The apartment valuation case centered on a 2022 appeal involving a property owner who challenged Albrecht’s valuation of about $13 million to $15 million and argued for a value near $8 million. Albrecht alleged Kramer appeared at the hearing even though he had not prepared the appraisal, blocked her from presenting her work and agreed during a recess to lower the value to $10 million. She alleged the lower figure lacked accepted appraisal methods. Kramer has also faced prior scrutiny over property dealings, including the use of gift deeds and financial disclosure questions. Prosecutors did not announce charges related to those past matters. Tuesday’s searches did not show whether federal investigators are examining any of those earlier disputes or a separate set of records.
At the Martinez office, the search disrupted a county department that handles property assessments, taxpayer records and appeal-related work. The closure came one week after the county’s election and as Robb prepared to take over the office when Kramer’s term ends. Kramer said he remains in office and was unsure when the assessor’s office would reopen. “I have been investigated more times than not,” Kramer said. “And every time, I am exonerated.” Federal agents did not hold a public briefing, and county officials did not say whether any temporary management changes would be made. The FBI also did not say whether Kramer, Robb or any other employee had been interviewed.
The investigation remained open Tuesday night, with no arrests, charges or next court date announced. The next public milestone may come if federal prosecutors seek to unseal more warrant records or file charges in federal court.
Author note: Last updated Tuesday, June 9, 2026.