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Probable Cause And DUIs

By November 23, 2020 January 12th, 2021 No Comments

The United States Constitution requires that law enforcement officers have a requisite level of justification before initiating a traffic stop or arresting anyone. In drunk driving cases, there are two thresholds of justification on which the police may rely. They are as follows:

  • probable cause” for a DUI arrest.
  • reasonable suspicion” for a DUI traffic stop.

These standards apply in all types of DUI cases, including offenses charged under California Vehicle Code § 23152(a) VC (driving while under the influence of alcohol), and violating California Vehicle Code § 23152(b) VC (driving with a BAC of .08 or higher). While theoretically, “reasonable suspicion” and “probable cause” are distinct standards, in practice, the two terms are used interchangeably in California DUI cases.

Regardless of the distinction, it is not uncommon that claims by the police of having either probable cause or reasonable suspicion to make a stop or arrest are ultimately found to be meritless. An experienced criminal defense attorney is adept at analyzing the facts of a stop or arrest and determining if police conduct was constitutionally valid. As a result of this analysis, a knowledgeable criminal defense attorney may file a motion to suppress evidence.

Often called a “suppression motion” or “1538.5 motion,” this motion is made either as part of the preliminary hearing or at a separate pretrial hearing. With this pretrial motion, a criminal defendant asks the court to exclude evidence obtained by way of an illegal search or seizure. If this motion is granted, the evidence is barred from introduction at trial.  This often results in case dismissal, or a more favorable plea agreement.

The Fourth Amendment to the United States Constitution prohibits unreasonable searches and seizures. Thus, a police officer must have probable cause or reasonable suspicion to make a stop or arrest. This means that the officer must be able to assert the presence of specific facts that caused the suspicion that a crime was in progress. The officer is not required to specifically suspect that the driver is under the influence of alcohol and/or drugs. Rather, any potential traffic infraction or violation is enough to satisfy the “reasonable suspicion“ threshold to make a stop provided that the underlying reasoning is valid and reasonable.

However, although reasonable suspicion permits a police officer to temporarily stop and detain a driver to further investigate when the officer believes the motorist may have committed a criminal offense, an officer must meet the higher standard of probable cause to make an arrest. This means that an officer has sufficient evidence to believe that it is probable or most likely that a motorist has committed a crime, thus justifying the arrest. For DUI stops, an officer may have probable cause for an arrest after administering a field sobriety test and/or a breath test if the results suggest intoxication.

Law enforcement officers must have reasonable suspicion to investigate a suspected DUI, which comes after a traffic stop or sobriety checkpoint. An investigation begins when an officer believes a driver may be guilty of driving under the influence. This investigation typically involves questions about whether, where, and how much the driver has been drinking; one or more field sobriety tests; and/or a preliminary alcohol screening test with a handheld breathalyzer.

Some examples of specific circumstances that may give rise to reasonable suspicion of a driver under the influence of drugs or alcohol and, therefore, may merit a traffic stop, include:

  • Making an illegal turn
  • Frequent braking
  • Drifting from one lane to another
  • Extremely slow or erratic driving (at closing time, a vehicle driving extremely slow or erratically after exiting a parking lot used by bar patrons)
  • Straddling the centerline
  • Stopping in the middle of the road unexpectedly
  • A vehicle running a red light

John Patrick Dolan has handled everything from traffic tickets to death penalty murder cases. Mr. Dolan has represented California motorists charged with DUI for over 40 years. He is a recognized California State Bar Certified Specialist in Criminal Law and a true courtroom veteran of DUI cases. Call the Dolan Law Offices today at (760) 775-3739 or find out more online here.

Probable Cause And DUIs