In the year since the jail abuse scandal erupted, Tanaka has come under heavy criticism. A county commission created to examine the jails accused Tanaka of exacerbating problems in the lockups by encouraging deputies to push legal boundaries and discouraging supervisors from disciplining deputies involved in misconduct.
The undersheriff admitted some fault, but denied that he turned a blind eye to abuse. In testimony before the commission, he accused his detractors of having personal agendas and trying to discredit him by misinterpreting his actions.
At least one witness has told the grand jury that another top sheriff's official — Lt. Greg Thompson, formerly in charge of the jailhouse intelligence team — was also involved in hiding Brown, according to the source.
Thompson was placed on leave last month. Sheriff's officials are investigating whether Thompson had his son, who is also a deputy, confront another jailer to find out what he had told the grand jury about the elder Thompson, according to several sources who asked to remain anonymous because the investigation is ongoing.
Representatives for the FBI and the U.S. attorney's office declined to comment. Whitmore said that Tanaka and Thompson also declined to comment.