When law enforcement stops you in California for suspected DUI, you may question whether you must submit to a breathalyzer test. The answer depends on the context—specifically, the timing and nature of the request.
Understanding the two types of tests
DUI investigations typically involve two types of breath tests. The first is a preliminary alcohol screening (PAS) test, conducted during the initial stop. The second is a post-arrest chemical test administered after formal arrest.
If you are 21 or older and not on DUI probation, you may lawfully decline the PAS test without incurring automatic penalties. Law enforcement primarily uses this device to assess probable cause for an arrest. However, the legal framework shifts significantly once you are taken into custody.
What happens if you refuse the post-arrest test
After an arrest, California’s implied consent law applies. By obtaining a driver’s license, you implicitly agree to submit to a chemical test—either breath or blood—following a lawful DUI arrest. Refusal to comply with this requirement carries immediate consequences.
Declining a post-arrest breathalyzer typically results in a mandatory driver’s license suspension of at least one year. Additionally, it may enhance penalties upon conviction and be introduced in court as evidence of your awareness of impairment.
Is refusal ever a good idea?
In limited scenarios, individuals assume that refusal might protect them by limiting available evidence. However, officers can proceed with an arrest based on behavioral cues, such as erratic driving, speech irregularities, or alcohol odor.
Moreover, a refusal often undermines your credibility. Prosecutors may assert that your refusal suggests a conscious attempt to obstruct the investigation or avoid legal accountability. Even absent a conviction, the Department of Motor Vehicles retains authority to suspend your license.
What you should remember
You retain the right to decline the roadside PAS test under certain conditions. However, once placed under arrest, refusal of a breath test triggers immediate and serious consequences. Distinguishing between these phases is essential when making informed decisions during a DUI investigation.