DUI Attorney in Diamond Bar

Reviewed by Ron Chini, Esq. · CA State Bar No. 263308 · DUI defense attorney in Irvine, CA since 2009.
About the author →

How DUIs are policed in Diamond Bar

Diamond Bar has never had its own municipal police department. Since incorporation, the city has contracted for law enforcement with the Los Angeles County Sheriff's Department, which patrols Diamond Bar out of the Walnut/Diamond Bar Station at 21695 E. Valley Blvd., Walnut, CA 91789 — a joint station that also covers the separate City of Walnut, Rowland Heights, and unincorporated Covina Hills and West Covina. A Diamond Bar resident dealing with a DUI arrest is dealing with Sheriff's deputies, not a city police force, which affects which agency's reports and bodycam footage a defense has to request.

On the freeways that frame the city — the SR-57/SR-60 interchange at Diamond Bar's northern edge, one of the busiest freeway interchanges in the San Gabriel Valley — DUI enforcement is handled by the California Highway Patrol's Baldwin Park office, which covers both SR-57 and SR-60 through Diamond Bar. A DUI arrest made directly on the 57/60 interchange itself is more likely a CHP stop than a Sheriff's stop, and that distinction matters for which agency's dashcam, radio traffic, and arrest report your attorney has to pull.

• Surface-street and neighborhood DUI stops: LA County Sheriff's Department, Walnut/Diamond Bar Station
• SR-57 and SR-60 freeway DUI stops, including the 57/60 interchange: California Highway Patrol, Baldwin Park office
• Sobriety checkpoints: coordinated by the Sheriff's station, sometimes jointly with CHP near the freeway interchange

Where a Diamond Bar DUI case is heard

Diamond Bar DUI cases are generally filed at the Pomona Courthouse, 400 Civic Center Plaza, the Los Angeles County Superior Court's East District complex that also handles cases from Pomona, Claremont, La Verne, and San Dimas. Some sources describe an older two-building arrangement, with a separate North building (350 W Mission Blvd) for misdemeanor matters — but whether that building is still taking filings isn't confirmed, so check your own citation or call the court clerk rather than assume either address. Independent legal-directory sources identify Diamond Bar as one of the cities routed to this courthouse.

Booking and getting a car back after a Diamond Bar arrest

A Diamond Bar DUI arrest made by Sheriff's deputies is typically processed first at the Walnut/Diamond Bar Station, with an arrestee held there only long enough for booking before being transferred into the county custody system — standard LASD practice routes adult arrestees toward the Inmate Reception Center (IRC) in downtown Los Angeles (men) or the Century Regional Detention Facility in Lynwood (women) for intake, rather than a long stay at the local station. If your vehicle was towed from a Diamond Bar stop, check with the Walnut/Diamond Bar Station or the towing company named on the impound slip. A standard DUI-related tow under Vehicle Code §22651(h) is released once a licensed driver claims it and pays towing and storage fees; a longer, 30-day hold under §14602.6 applies only if the driver was unlicensed, suspended, or revoked at the time of the stop.

Diamond Bar's identity: a planned community at the 57/60 interchange

Diamond Bar incorporated on April 18, 1989, making it one of the newer cities in Los Angeles County, and it was built out as a master-planned residential community rather than growing up around an older downtown. The city sits at the junction of the SR-57 (Orange Freeway) and SR-60 (Pomona Freeway), and that interchange — along with Diamond Bar Boulevard, the city's main commercial spine — is where a large share of local traffic stops and DUI enforcement happen. Diamond Bar is also home to one of the larger Chinese-American and Korean-American communities in the San Gabriel Valley: Census data shows Chinese ancestry makes up roughly 48% of the city's Asian population and Korean ancestry roughly 26%, and Chinese (including Mandarin and Cantonese) is the most common non-English language spoken in Diamond Bar households, ahead of Spanish and Korean. The city-owned Diamond Bar Center, a 22,500-square-foot event facility overlooking the San Gabriel Valley from Summitridge Park, is a well-known local landmark and gathering spot distinct from anything in the surrounding cities.

← Back to Los Angeles County DUI Defense

Ron Chini, Esq.

DUI Defense Attorney · CA State Bar No. 263308

Ron defends DUI cases across Southern California from his Irvine office, in English and Farsi — and works directly with you, not a call center.

Learn more about Ron Chini →