Vehicle Code 23578 is the high blood-alcohol sentencing factor: it tells the court to treat a blood-alcohol concentration of 0.15 percent or more, or a refusal, as an aggravating factor when sentencing a DUI. I am Joel Brand, and here is what it means and how I limit its effect.
The text of the law
Vehicle Code 23578. In addition to any other provision of this code, if a person is convicted of a violation of Section 23152 or 23153, the court shall consider a concentration of alcohol in the person's blood of 0.15 percent or more, by weight, or the refusal of the person to take a breath or urine test, as a special factor that may justify enhancing the penalties in sentencing, in determining whether to grant probation, and, if probation is granted, in determining additional or enhanced terms and conditions of probation.
What the statute does
Section 23578 is not a separate crime and not a fixed enhancement. It is a sentencing-factor statute: it directs the court to treat a high blood-alcohol level of 0.15 percent or more, or a chemical-test refusal, as a "special factor" that may justify a harsher sentence, may weigh against granting probation, and may support tougher probation conditions. In practice, a high reading often translates into a longer DUI program, additional conditions, and a firmer stance from the prosecution. It gives the court discretion to be harsher, but it does not mandate a specific penalty.
It only matters after a conviction
The most important thing to understand is that 23578 applies only "if a person is convicted." It is a sentencing consideration, not an element the prosecution proves to win the case, and it has no role at all unless and until there is a conviction. That means the first and best way to neutralize it is to defeat or reduce the underlying DUI. If the charge is dismissed or reduced to a wet reckless, this aggravating factor never comes into play.
The 0.15 reading can be challenged
Because the factor turns on a specific number, the reliability of the chemical test is squarely in issue. A breath or blood result of 0.15 is not beyond challenge: instrument calibration, the fifteen-minute observation period, mouth alcohol, blood-sample handling and fermentation, and the timing of the test relative to driving can all affect the number. If the true level was below 0.15, or the measurement is unreliable, the aggravating factor loses its footing. I scrutinize the testing just as closely for sentencing as for guilt, because keeping the reading under the threshold can meaningfully soften the sentence.
The refusal alternative
The statute also lets the court treat a refusal as the aggravating factor. That overlaps with the separate, mandatory refusal enhancement under Vehicle Code 23577, and it raises the same questions: was the refusal willful, and was the admonition proper? Where the refusal finding is defeated, both the 23577 enhancement and the 23578 aggravating factor fall away. I challenge the refusal once, and the benefit flows to both.
Arguing against aggravation at sentencing
Even where a high reading or refusal is established, 23578 gives the court discretion, not a command. That leaves real room to argue for leniency by presenting the full picture: the absence of any accident, a clean prior record, voluntary enrollment in counseling or a program, and other mitigating circumstances. A single number does not define a person, and I make sure the court weighs the mitigating factors against the aggravating one rather than letting the reading dictate the outcome by itself.
How it interacts with the high-BAC charge
A 0.15 reading frequently appears together with the prosecution's emphasis on a high blood-alcohol level throughout the case. The defense to the reading is the same whether it is used to prove the charge or to aggravate the sentence, which means a strong challenge to the chemistry serves double duty. I develop the attack on the test once and apply it both to guilt and to sentencing.
How these cases resolve
The realistic goals are to defeat or reduce the underlying DUI so the factor never applies, to challenge the 0.15 reading or the refusal finding that triggers it, and, where a conviction stands, to argue the mitigating circumstances so the court does not impose the harsher options the statute permits. Because 23578 is discretionary, persuasive sentencing advocacy genuinely matters here. As always, the outcome depends on the strength of the evidence, which I evaluate in full.
Why the rising-alcohol issue matters here
One scientific point is especially powerful when a reading sits near 0.15. Alcohol takes time to absorb, so a person's blood-alcohol level can still be climbing for a period after the last drink. A test administered well after the driving may capture a peak that was not present behind the wheel, which means the number used to aggravate the sentence may overstate the level at the actual time of driving. Combined with the inherent margin of error in breath and blood testing, this absorption dynamic can place a reported 0.15 in genuine doubt. I raise these issues not only to contest guilt but to keep a borderline reading from being treated as a settled aggravating fact at sentencing, because a number that cannot be relied upon should not be used to justify a harsher result, and I make that point with the supporting science rather than as a bare assertion.
How it fits the larger defense
Section 23578 is a sentencing factor, defended through the same challenges to the chemistry and the refusal that drive the rest of the case. It connects directly to the refusal enhancement and the high-BAC issues in any DUI. See my top DUI defenses and the defenses guide.
Facing a high-BAC or refusal DUI? Let's talk.
Keeping the reading and the refusal from driving your sentence is exactly what I do. Use the free case analysis on this page, or call me directly at (888) 271-6644. I answer my own phone, 24/7.