CONTRA COSTA, CA — A district attorney's inspector who struck and killed a man running across Highway 4 will not face criminal charges following a review of the incident.
The Alameda County District Attorney's Office reviewed the 2025 crash that killed Phoenix Corwen Dunn, 27.
Contra Costa County prosecutors requested the outside review because the driver, Senior Inspector Sean Eriksen, worked for their office.
The incident began Dec. 22, 2025 at about 10:30 a.m., when a security guard at the Comfort Inn, now Antioch Inn & Suites, called 911 to report that a man had pulled a fire alarm and fled.
The guard chased Dunn to a nearby bowling alley and tried to detain him. Dunn broke free during a struggle and ran behind the Kaiser Permanente Delta Fair Medical Offices.
An Antioch police officer responding to the call spotted Dunn in the medical offices' parking lot. Dunn climbed a fence and entered Highway 4 near the Somersville Road offramp.
In an initial account, Antioch police said responding officers did not pursue Dunn on foot, Patch reported on December 24, 2025. That report identified the freeway's direction as eastbound.
Dunn crossed several lanes in moderate to heavy traffic before Eriksen's car struck him in the left lane. Eriksen was on duty.
A CHP officer driving directly behind Eriksen witnessed the collision. A passing motorist stopped and performed lifesaving aid, but Dunn was pronounced dead at 10:49 a.m.
Eriksen suffered minor injuries, remained at the scene, and gave a voluntary statement. The county coroner later classified Dunn's death as an accident.
Witness accounts and video showed Dunn entered the freeway suddenly, according to the CHP investigation.
Pedestrians are prohibited on that stretch of freeway.
The California Highway Patrol spent about six months reconstructing the crash and concluded it was unavoidable, according to the Contra Costa District Attorney's office.
Investigators found Eriksen's county car in proper working order and uncovered no evidence that he was impaired, distracted, or driving unsafely.
Alameda County prosecutors found no evidence supporting murder or manslaughter charges and concluded that no further criminal inquiry was warranted.
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