In Arizona, police need what is known as ‘probable cause’ in order to make a DUI arrest. That means that before the police can arrest someone for a DUI in Arizona, the police must have probable cause to believe both that the crime of DUI has been committed, and that the person being arrested actually committed the crime. But what exactly is and constitutes probable cause?

In order to have probable cause, the police must have enough information that would make a reasonable person believe that the driver was driving while intoxicated. Mere suspicion that the person was DUI is not enough; the police must point to specific facts that made them believe that the person violated a DUI law for there to be probable cause.

Typical facts that Arizona police officers point to in order to attempt to establish probable cause for DUI arrests are:

  • Admissions of drinking
  • Field sobriety test results (such as results from a ‘walk-and-turn’ test, ‘one-leg-stand’ test, etc.)
  • Portable breath test (PBT) results
  • HGN results (often referred to as the ‘pen test’)
  • Odor of alcohol
  • Bloodshot and watery eyes
  • Flushed face
  • Slow speech
  • Thick speech
  • Slurring of words
  • Driving behavior
  • Traffic violations
  • Trouble producing requested documents (such as driver’s license, registration, and/or proof of insurance)
  • Trouble exiting the vehicle
  • Difficulties with walking or standing

Although this list is certainly not comprehensive since there are many other facts that an Arizona police officer may cite when attempting to establish probable cause for a DUI arrest, it gives you an idea of what they will point to when establishing that they had probable cause for the DUI arrest.

In some Arizona DUI cases, however, it may not be clear that the police officer actually had probable cause to make the DUI arrest, even if they cite to a few of the examples listed above. A good DUI defense attorney will review the specific facts of each individual case, and determine if there is a question as to whether probable cause for the DUI arrest existed in the case. If it appears that the police lacked probable cause, the attorney will raise the issue to the court and place the burden on the State of Arizona to establish that the police had probable cause to arrest the person for DUI.