SAN DIEGO, CA – Motorists arrested for driving under the influence of controlled substances in San Diego County face aggressive prosecution under California Vehicle Code Section 23152(f), with penalties that escalate sharply for repeat offenses. San Diego DUI defense attorney Anna R. Yum of the Law Offices of Anna R. Yum (https://www.annayumlaw.com/practice-areas/san-diego-dui-lawyer/drugs-duid/) is providing guidance on how the statute is applied, what investigators look for after a traffic stop, and what defense strategies may be available to those charged.
According to San Diego DUI defense attorney Anna R. Yum, VC 23152(f) makes it unlawful for any person under the influence of any drug to operate a motor vehicle, and unlike alcohol-related charges, there is no per se chemical threshold that automatically establishes guilt. Prosecutors must rely on officer observations, Drug Recognition Expert evaluations, and toxicology results to prove that the substance actively compromised driving ability. “Without a fixed legal limit, the prosecution’s case in a drug DUI often depends on subjective interpretation of physical signs, and that opens the door to substantial defense challenges,” explains Yum.
San Diego DUI defense attorney Anna R. Yum notes that the law applies not only to illegal narcotics but also to legally obtained prescription medications and over-the-counter products that can affect driving ability. A valid prescription is not a defense if the medication impaired the driver’s motor skills or judgment. The California Department of Motor Vehicles confirms that the law treats prescription substances and illegal narcotics the same when impairment is at issue, and prosecutors regularly pursue charges involving sleep aids, prescription opiates, anti-anxiety medications, and stimulants when these substances appear in a driver’s blood test.
Yum points out that the consequences of a conviction grow severe with each prior offense within a ten-year window. A first offense is generally a misdemeanor carrying up to six months in county jail, base fines of $390 to $1,000, license suspension of up to six months, and three to nine months of court-ordered DUI school. A fourth offense within ten years is charged as a felony and exposes the defendant to 16 months, two, or three years in county jail under California’s realignment laws, along with fines that can reach $5,000 and license suspension of up to four years. Mandatory court penalty assessments can multiply base fines several times over.
The firm emphasizes that drug DUI investigations follow a different procedural path than standard alcohol DUI cases. Because no roadside breath test exists for narcotics or prescription medications, officers depend on field sobriety tests, observations of physical indicators such as pupil size and pulse rate, and the 12-step evaluation conducted by a Drug Recognition Expert. Each step in the DRE protocol creates an opportunity for defense scrutiny. If the evaluating officer skipped steps, deviated from the standardized procedure, or reached conclusions inconsistent with the physical evidence, the entire evaluation can be challenged and the testimony potentially suppressed.
The Law Offices of Anna R. Yum represents clients throughout San Diego County, including Chula Vista, El Cajon, Escondido, National City, and Oceanside. Drug DUI cases in San Diego are handled through the San Diego Superior Court system, and the San Diego County District Attorney’s Office regularly pursues VC 23152(f) charges when blood test results confirm the presence of a controlled substance, even where the DRE evaluation was incomplete.
“Blood test evidence in a drug DUI case is only as reliable as the procedures used to collect, store, and analyze the sample,” advises Attorney Yum. “California Code of Regulations, Title 17, sets strict requirements for chain of custody, sample preservation, and laboratory protocols. Violations at any of these stages can support a motion to exclude the test results entirely.” Separate from the criminal case, the California DMV initiates an Administrative Per Se action to suspend driving privileges, and the driver has only ten days from the date of arrest to request an APS hearing.
Yum also notes that several defenses can apply, including challenges to the legality of the traffic stop, the qualifications and methodology of the Drug Recognition Expert, and the reliability of blood test results. Medical conditions such as illness, fatigue, anxiety, diabetic ketoacidosis, naturally occurring nystagmus, and ear conditions affecting balance can produce symptoms that mimic impairment. Trace amounts of certain substances, particularly when discussing the active compound in lawful adult-use products, can remain detectable in the bloodstream for days or weeks after consumption without causing actual impairment at the time of driving, which complicates the prosecution’s reliance on toxicology alone.
For those facing charges under VC 23152(f) or the related provisions of VC 23152(c) or VC 23152(g), prompt action protects both the criminal case and driving privileges. The firm offers a no-cost case evaluation to review the circumstances of the arrest, identify defense opportunities, and manage both the criminal proceeding and the DMV APS hearing simultaneously. Contacting an experienced San Diego DUI defense attorney as soon as possible after arrest can make a significant difference in the outcome.
About Law Offices of Anna R. Yum:
Law Offices of Anna R. Yum is a San Diego-based criminal defense firm dedicated to representing clients charged with DUI, DUI involving controlled substances, and other felony and misdemeanor offenses throughout California. Led by attorney Anna R. Yum, a former Riverside County Deputy District Attorney, the firm serves clients in San Diego, Chula Vista, El Cajon, Escondido, Oceanside, and surrounding San Diego County communities. The office is located at 1230 Columbia St #1140, San Diego, CA 92101. For consultations, call (619) 233-4433.
Email: ayum@annayumlaw.com
Media Contact
Name
Law Offices of Anna R. Yum
Contact name
Anna R. Yum
Contact phone
(619) 233-4433
Contact address
1230 Columbia St #1140
City
San Diego
State
CA
Zip
92101
Country
United States
Url
https://www.annayumlaw.com/
