One of the most confusing issues among clients that we represent is the concept of the arrest after a DWI traffic stop. The question becomes when an actual arrest occurs after the initial DWI traffic stop. Many individuals think that they are under arrest simply when they are pulled over and asked to perform a variety of field sobriety tests. The next inevitable question is “why were my Miranda rights not read to me at this point”? The Miranda rights issue is a whole subject in and of itself that we have previously written about.
Before a police officer can place a driver under arrest for driving under the influence of alcohol or a controlled substance, he or she must first establish that probable cause exists for the arrest. An arrest exists when the driver is placed in a custodial position by the police officer and when the individual is clearly not free to leave on his or her own. Many people equate an arrest with being placed in handcuffs. But, being placed in handcuffs is not a requirement for a driver to be considered placed under arrest.
There are several factors a police officer will consider before deciding whether probable cause exists to place a driver under arrest for DWI. First, the officer will consider the manner in which the vehicle was driven by the suspect which warranted the initial traffic stop. For instance, whether the motor vehicle was weaving or crossing traffic lanes in an erratic manner or without signalling. Usually, any driving conduct that would be considered inattentive may be evidence of impairment. Second, once the traffic stop has occurred, the officer will consider the manner in which the driver is acting and his or her physical appearance or speech. Additional evidence of physical appearance to establish probable cause will be how the driver appeared upon exiting their vehicle and whether they had difficulty balancing upon exit.
Once the driver is outside of the motor vehicle, the police officer will usually ask the individual to perform a variety of field sobriety tests to further aid the officer in establishing probable cause. Some of the more common or universal tests are: Horizontal Gaze Nystagmus or HGN test, heel to toe, stand on one leg and numerical counting or reciting the alphabet. The officer will have a certain criteria in which he or she has been trained to use in determining if the driver has passed or failed these tests.
In addition, one of the last tests the officer will generally require of the driver before deciding whether to place someone under arrest is some form of preliminary breath test or PBT. This is usually a handheld breath test that is used by the officer to indicate whether an individual may be above the legal limit. In Minnesota, the PBT test is not admissable at trial by the prosecution as evidence that an individual is over the legal limit. However, most officers find this as a valuable tool in determining whether they have probable cause to make an arrest for driving under the influence.
In a future post, we will detail what happens after a DWI arrest in Minnesota.