The calls followed a confrontation at the Oakland waterfront offices of California Waste Solutions, where Juarez said he had been beaten by about 10 people. He alleged the company’s owners had arranged the assault and suggested police officers might be involved. Those claims have not been substantiated, and the people involved offer sharply different accounts of what happened.

FBI Special Agent Katherine Barclay testified that Oakland police shared Juarez’s allegations with federal investigators because they included claims about the department. The FBI then interviewed Juarez, whose information became part of an investigation that had already been examining a potential bribery scheme, Barclay said.

The federal trial, which began this month in Oakland, centers on former Mayor Sheng Thao, her longtime partner Andre Jones, and California Waste Solutions owners David and Andy Duong. They are charged with bribery, conspiracy and honest-services mail and wire fraud. Prosecutors allege the defendants arranged political favors and benefits for the Duongs’ businesses, including a no-show job and negative campaign mailers. All four have pleaded not guilty.

The calls came as Juarez’s business relationship with the Duongs was collapsing. The three had partnered in 2022 on Evolutionary Homes, a venture intended to turn shipping containers into housing for people leaving homelessness. Prosecutors allege Thao agreed to have Oakland buy units from the company as part of the alleged corruption scheme.

The Duongs told an Alameda County district attorney’s office inspector they had invested $800,000 in the venture and believed Juarez had misused the money. They said he was supposed to deliver 50 homes but produced only two. A search warrant affidavit described their investment as having grown to slightly more than $1 million before they decided to end the partnership.

Prosecutors say Juarez was frustrated that the Duongs would not reimburse expenses he said he had incurred. In an April 2024 email to the Duongs and others, Juarez warned that they could be contacted by the FBI, city attorneys and state campaign regulators, according to a court filing.

On May 3, Juarez went to the company’s office and found himself locked out, prosecutors say. An audio recording played in court captures him demanding his money, while David Duong says the family wants its investment back and that the business is closed. Prosecutors say Andy Duong recorded the exchange and that people later arrived and assaulted Juarez, taking a watch and chain. They say agents found the items in a paper bag in Andy Duong’s garage during a later search; Juarez identified them as his.

Juarez called police that day and again the next morning, saying he had been assaulted and asking for a sergeant. He alleged the Duongs had influence with officers. Oakland police said the department shared the information with the FBI and has cooperated with federal authorities. It declined to discuss Juarez’s statements or whether any officers faced discipline, citing restrictions on disclosure of personnel records.

The Duongs’ account differs. Andy Duong told the inspector that Juarez came to the office demanding money and kept the family there for hours; he alleged Juarez was known to carry weapons. Andy Duong’s attorney, Winston Chan, told jurors that Juarez arrived agitated and armed, and that a person outside the family punched him. Chan acknowledged there was an altercation but said it was not a planned ambush. A photo taken outside the office that day shows Juarez on the ground, covered with a blanket, with an ambulance nearby.

Defense lawyers have also challenged Juarez’s credibility, citing court records they say show he was sued about 33 times from 1992 to 2022 and had repeatedly made accusations against business partners. Prosecutors have argued that Juarez’s earlier observations about security footage are relevant because no surveillance video from the company’s headquarters on the day of the confrontation exists. Juarez previously told the FBI he saw members of the Duong family delete footage, according to a prosecution filing.

Juarez met with the FBI on June 6, 2024. Two weeks later, agents searched the homes of Thao, Jones and the Duongs. Federal officials have declined to comment on the case, which remains before the jury.