Humboldt County sheriff’s deputy Luke Mathieson set to join DA’s office

A familiar face from Courtroom 3 is headed from the Humboldt County Sheriff’s Office to the district attorney’s investigative team, a move that pulls an experienced deputy out of one part of county law enforcement and places him directly inside the prosecution side of the system.

Luke Mathieson, currently serving as the Courtroom 3 bailiff, was identified as waiting on a background check and expected to become a Humboldt County District Attorney investigator. The transfer matters because it does more than change one badge assignment: it moves an experienced law enforcement officer from sheriff’s operations into the office that builds cases, prepares warrants and supports prosecutors in court.

The Humboldt County District Attorney’s Office says its Criminal Investigations Division is led by Chief Kyla Baxley and is staffed entirely by experienced law enforcement officers. That division handles civil and criminal investigations, prepares and executes search and arrest warrants, investigates elder abuse cases, locates and interviews witnesses, processes evidence, and assists local law enforcement agencies on major cases. With Mathieson joining that unit, the DA’s office gains another investigator who already knows Humboldt County’s courtroom and jail-side rhythms.

That gain comes as a loss for the sheriff’s office, which has been under the same staffing strain affecting other parts of the local justice system. In May 2025, attorneys from both the district attorney’s office and the public defender’s office told the Humboldt County Board of Supervisors they were underpaid and overworked, and warned that more departures could follow amid the county’s budget pressure. Mathieson’s move fits that larger picture of turnover and competition for experienced personnel inside Humboldt County government.

The district attorney’s office says it was established in 1853 and now includes about 60 professionals, among them 14 deputy district attorneys, 5 victim advocates and 11 investigators. Those numbers underscore how much the office depends on investigators like Mathieson to keep serious matters moving, especially the sensitive cases that come in from local police agencies and the sheriff’s office.

The transfer also lands in the middle of Humboldt County’s critical incident response structure, where the district attorney’s office often leads reviews alongside the sheriff’s office, Eureka police, Arcata police and other allied agencies. In those investigations, the DA’s office does not operate in isolation; it depends on close coordination with the same agencies that will now be one deputy short while the prosecution side adds one more experienced hand.