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How Police Determine Probable Cause in DWI Cases

Posted by Tilem & Associates, PC || 24-Jan-2017

You’re driving the home from a friend’s house, a work function, or a dinner party when you notice bright flashing lights in your rearview. As you pull over to the side of the road, you question how much alcohol you drank before getting behind the wheel. Can the police arrest you immediately after pulling you over for DWI? Not without probable cause to do so.

What is probable cause then? Probable cause is circumstantial evidence seen by police prior to stopping you or during their stop that could lead them to make the reasonable assumption that the driver is intoxicated. This law is purposefully vague to allow police to use their own discretion when choosing to arrest a suspect.

Police consider the following probable cause for a DWI arrest:

  • Smells like Alcohol: If you roll down your window and the police smell alcohol on your breath or in your car, this could be considered evidence in plain sight. This is often how DWI investigations begin.
  • Failed Nystagmus Gaze Test: When an officer suspects a driver of driving while under the influence, they can request the driver perform a series of standardized field sobriety tests. One of the most commonly used field sobriety tests is the Horizontal Gaze Nystagmus test. During this test, an officer will ask the driver to follow a pen or other object with their eyes as they pass the object from one side of the suspect’s gaze to the other. If you fail this test, this could lead to you being asked to perform other field sobriety tests, to blow into a portable breath screening test or being asked to take a chemical test at the police station.
  • Swerving or Failure to Maintain: Erratic driving, swerving between lanes, and excessive speeding could be considered probable cause for stopping a driver and could add to the suspicion that the driver is intoxicated.
  • Portable Breath Screening Tests: Sometimes a police officer will ask you to blow into a portable breath machine. While the results of such test are generally not admissible at trial, a positive breath screening test may result in you being taken to the station for a chemical test. Refusal to take the portable breath screening test will not result in suspension or revocation of your driving privileges but it is a traffic infraction punishable by a fine and two pints on your license to refuse this test.
  • Breathalyzer Results: In most states, you give implied consent to the breathalyzer tests by holding a valid license. If an officer believes they have probable cause that a driver was operating their vehicle while under the influence, New York laws of implied consent give that officer the ability to perform and chemical test to check their BAC levels. If you are found to have refused a properly demanded test your driving privileges will be revoked for a minimum of one year.
Arrested for DWI? Get Legal Help Now!

At Tilem & Associates, we pride ourselves on our tenacity. Our attorneys are experienced with DWI and DWAI cases and know the law and the science behind DWI cases. We will fight tirelessly to help you get the best possible results in your DWI. With years of experience under our belts, our White Plains DWI lawyer is the right choice for you. Call today!

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