What is Probable Cause in Ventura?

DUI Investigations & Probable Cause

The term “DUI investigation” refers to the information that a police officer uses to justify a drunk driving arrest. This might include repeated, DUI-related questions like “Were you drinking tonight?” and field sobriety testing. Breathalyzer testing or other forms of alcohol screening can constitute an investigation as well. In order to start a DUI investigation, the officer must have a reason to believe that you are under the influence of alcohol. Without probable cause for a DUI investigation, any information that the officer collects during the investigation may be inadmissible in court.

Although the law does not specify the articulable facts that constitute probable cause for a DUI investigation, police reports usually indicate one or more of the following evidences:

• The driver had an open container or alcohol in the car
• The driver smelled like alcohol
• The driver’s eyes were watery
• The driver’s face was red
• The driver exhibited any symptom of intoxication

Without one of these facts (or similar evidence), any chemical testing or field sobriety tests conducted after the traffic stop may not be admissible in court.

Police Cannot Make a DUI Arrest Without Probable Cause

After a DUI investigation, law enforcement cannot conduct a DUI arrest without further evidence that the driver is intoxicated.

Probable cause from a DUI arrest usually involved chemical or field sobriety testing; an officer might smell alcohol on a driver’s breath, request a breathalyzer test, and arrest the driver if the test indicates that his / her BAC is over the legal limit. Field sobriety tests are another common probable cause for a DUI arrest. If the office does not discover new evidence of intoxication or cannot articulate the reason that he /she suspected DUI, the court may consider it a wrongful arrest.

1538.5 Suppression Hearings & DUI Evidence

According to California Penal Code § 1538.5(B)(iii),

A defendant may move for the return of property or to suppress as evidence any tangible or intangible thing obtained as a result of a search or seizure on either of the following grounds: The search or seizure with a warrant was unreasonable because…there was not probable cause for the issuance of the warrant.

In other words, California allows defendants the opportunity to suppress any evidence held against them that was obtained without probable cause. This law applies DUI cases as well. Although suppression hearings are not always successful, defense lawyers often use them as part of a case strategy. In a DUI case, you may be able to file a successful motion to suppress evidence if the arresting officer:

• Pulled you over, even though you didn’t commit a traffic infraction
• Detained you without any symptoms of intoxication
• Arrested you even though you passed field sobriety testing
• Arrested you even though you had one drink and were not intoxicated