A former Santa Clara County jail guard who prosecutors say helped set up an inmate ambush at the Elmwood men's facility has been ordered to spend time in a cell himself.
Today, ex-deputy Francisco Izayas Castillo was sentenced to 45 days in jail after a misdemeanor battery conviction tied to a Sept. 21, 2022 attack inside Elmwood's Module 4C. Judge Brooke Blecher told Castillo to report to custody on June 9, 2026. Prosecutors argued the case shows how a single deputy's choices can open up deadly gaps in county jail security.
According to The Mercury News, a jury found Castillo guilty on March 13 of misdemeanor battery for his role in the 2022 assault. The Santa Clara County Sheriff's Office fired him in November 2024. Prosecutors had pushed for a 60-day term, while court records also show that another man, Joseph Hernandez, pleaded no contest to misdemeanor battery for acting as a lookout. District Attorney Jeff Rosen is quoted in the coverage, calling Castillo's conduct a betrayal of both the public and the badge.
The Elmwood Correctional Complex in Milpitas houses male inmates and has been under recurring scrutiny over safety reviews and in-custody incidents. The Santa Clara County Sheriff's Office outlines Elmwood's housing units and its procedures for investigating incidents, reflecting the continued focus on how fights and assaults are handled within the jail.
How Prosecutors Say It Unfolded
In court, prosecutors described a setup that started at a control panel. They said Castillo used his control station to remotely unlock the victim's cell, then told two inmate trustees, identified in filings as Adrian and Roney Martinez, to "handle it." He then turned off the cell's emergency alert, clearing the way for the beating, according to The Mercury News.
The outlet reports that other inmates did not notice the victim's head injuries until roughly 13 hours later. Investigators also say a second deputy improperly used a virtual attorney meeting to question the injured inmate and pull out corroboration about what happened.
Castillo's attorney, Nelson McElmurry, told reporters that his client "absolutely maintains his innocence" and intends to keep fighting the conviction.
Legal Notes
Castillo was convicted of misdemeanor battery based on a case that relied on internal jail logs, witness statements and text messages that prosecutors said tied him to the assault setup. Another inmate admitted to a lookout role by pleading no contest to a misdemeanor battery charge, and the defense has signaled it will pursue post-conviction remedies.
Judge Blecher's order that Castillo report to jail on June 9 gives county watchdogs and jail advocates a firm date to circle as they continue to track oversight at Elmwood. County officials declined to go beyond previously filed statements on the incident, while the defense reiterated its plans to challenge the verdict.
