November 3, 2025 By Paul Wallin

Things To Know When Facing A DUI Trial: Prior Enhancements

When facing DUI charges in California, your past can significantly impact your future. Prior DUI convictions don’t just disappear after a few years—prior DUI convictions will be used to enhance penalties for new offenses, leading to more severe consequences including longer jail sentences, higher fines, extended license suspensions and even result in charges for murder if someone is killed due to you driving while under the influence and you have a prior DUI conviction. 

Our experienced criminal defense attorneys at Wallin & Klarich can guide you through the legal process. Call Wallin & Klarich today toll-free at (877) 466-5245 for your free consultation with one of our criminal defense attorneys near you.

The 10-Year Limit on Prior Offenses

California law establishes a timeframe for when prior DUI offenses can be used to enhance current charges. Under this law, if a DUI offense has been committed and within 10 years of another offense and there was a conviction, it will qualify as an enhancement. This 10-year period is measured from the date of commission of one offense to the date of commission of another offense. The law doesn’t look at conviction dates or sentencing dates—it specifically focuses on whether the underlying criminal acts occurred within 10 years of each other AND there was a prior conviction under one of the applicable statutes. 

Understanding the Complexities of Prior Offense Timing

California’s approach to prior offense timing contains an important provision that significantly impacts cases. Based on the statute under Vehicle Code Section 23217, a prior offense will be counted even if it was committed after the later offense if that later offense resulted in a conviction prior to the conviction in the earlier offense. This rule means that the chronological order of offenses isn’t always determinative. What matters is whether a prior conviction exists at the time of sentencing for the current offense and whether the time frame in which the offenses occurred are within 10-years of each other. 

Qualifying Offenses Under California Law

Not every alcohol or drug-related driving offense qualifies for enhancement purposes. California Vehicle Code Section 23550 specifically lists the qualifying offenses found in Vehicle Code Sections 23152, 23153, and 23103.5. These include:

Vehicle Code Section 23152: Standard DUI offenses, including  driving under the influence of alcohol, drugs, or both. As well as driving with a blood alcohol concentration of 0.08% or higher.

Vehicle Code Section 23153: DUI causing injury, which involves driving under the influence and causing bodily injury to another person.

Vehicle Code 23103: Otherwise known as a “wet reckless” with the “wet” component acknowledging alcohol involvement under (Vehicle Code 23103.5) is a reduced charge from Vehicle Codes section(s) 23152 and 23153. However, a “wet reckless” conviction will also be considered a prior DUI offense as outlined in vehicle code section 23103.5(c) so long as the offense occurred within 10 years. 

Out-of-State and Federal Convictions

California’s enhancement laws extend beyond state borders. Under Vehicle Code Sections 23626 and 13352(d), out-of-state, federal, and even Canadian DUI convictions can constitute qualifying priors if the convictions are based on legislation substantially similar to California’s legislation. 

This provision means that a DUI conviction from other states, U.S. territories, the District of Columbia and Canada can be used to enhance a California DUI charge, provided the out-of-state law contains similar elements to California’s DUI statutes. Courts will examine the specific language and requirements of the foreign jurisdiction’s law to determine whether it’s substantially similar enough to qualify and if the offense were committed in this state, would be a violation of Section 23152 or 23153, or Section 191.5 of, or subdivision (a) of Section 192.5 of, the California Penal Code.

What Doesn’t Count: Constitutional and Juvenile Issues

California law provides important limitations on what types of prior convictions can be used for enhancement. Constitutionally invalid convictions under Vehicle Code Section 41403 cannot be used as priors. This protection ensures that convictions obtained in violation of constitutional rights—such as those resulting from ineffective assistance of counsel or other due process violations—don’t unfairly enhance future sentences. Similarly, juvenile adjudications generally cannot be used as priors for DUI enhancement purposes. 

Challenging Prior Enhancements

Despite the serious nature of prior enhancements, several defense strategies may be available, such as:

  • Carefully calculating the 10-year lookback period and challenging whether prior offenses actually fall within the statutory timeframe.
  • Examining prior convictions for constitutional violations that would render them invalid for enhancement purposes.
  • For out-of-state convictions, challenging whether the foreign jurisdiction’s law is truly substantially similar to California’s DUI statutes.
  • Ensuring that court records accurately reflect the dates and nature of prior offenses, as clerical errors can sometimes affect enhancement calculations.

When facing potential prior enhancements, early legal intervention is critical. The Prosecution bears the burden of proving prior convictions, but this proof often comes through certified court records that can be difficult to challenge once admitted into evidence. An experienced attorney can examine these records and identify potential issues early in the criminal proceedings. 

Contact Wallin & Klarich Today  

If you are facing DUI charges, you need to contact an aggressive defense attorney to fight for your freedom. With 40+ years of experience, our attorneys at Wallin & Klarich have helped many clients ensure they receive a fair trial in their criminal defense cases. We know the most effective strategies to argue on your behalf, and we will do everything in our power to help you achieve the best possible result in your case.

At Wallin & Klarich, we have offices all over Southern California: Irvine, Pasadena, Riverside, San Bernardino, San Diego, Torrance, and Anaheim. Additionally, our law firm can handle many types of cases statewide.
Discover how our team can assist you. Contact us today, toll-free at (877) 466-5245 for a free consultation with a skilled criminal defense attorney near you.

Paul Wallin

AUTHOR: Paul Wallin

Paul Wallin is one of the most highly respected attorneys in Southern California. His vast experience, zealous advocacy for his clients and extensive knowledge of many areas of the law make Mr. Wallin a premiere Southern California attorney. Mr. Wallin founded Wallin & Klarich in 1981. As the senior partner of Wallin & Klarich, Mr. Wallin has been successfully representing clients for more than 30 years. Clients come to him for help in matters involving assault and battery, drug crimes, juvenile crimes, theft, manslaughter, sex offenses, murder, violent crimes, misdemeanors and felonies. Mr. Wallin also helps clients with family law matters such as divorce and child custody.

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