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Reasonable suspicion and impairment tests in DUI cases

On Behalf of | Apr 1, 2020 | Firm News

A person who is facing a drunk driving charge often has various options to consider as components of their defense strategy. One of these might be calling the validity of the traffic stop into question. In order to stop a vehicle, the police officer needs to have reasonable suspicion that the law was violated.

Reasonable suspicion is a much lower standard than probable cause. The officer doesn’t have to actually see a person break the law. Instead, they only have to see signs that the person might be breaking the law. There are several signs of drunk driving that they might look for when patrolling.

Signs of drunk driving that provide reasonable suspicion

Drivers who are impaired by anything, including alcohol, drugs or medications, are likely to exhibit some specific signs when they’re on the road. Officers will look for drivers who:

  • Turn illegally and without a signal
  • Straddle the center line
  • Brake frequently
  • Almost hit objects on the side of the road
  • Stop in the middle of the road without reason
  • Drift between lanes
  • Serve through multiple lanes
  • Fail to turn on headlights when necessary
  • Drive too fast or slow for conditions

An officer who pulls a vehicle over for the suspicion of drunk driving will try to find out what’s going on. This is their chance to try to ensure that the motorist isn’t having a medical emergency that might require help.

Methods for determining impairment

Drivers who are likely impaired may be asked to take a field sobriety test. There are several of these the officers might conduct, but there are only three that are part of the standardized field sobriety test that can be used in court – horizontal gaze nystagmus, one-leg turn, and walk and turn.

When the officer believes that the person is impaired, they may ask them to take a chemical test. This comes in several forms, including a breath, blood or urine test. Using a portable breath test at the scene can provide a preliminary result, but the person would also have to do a more accurate test at a medical center or via a stationary breath test machine that’s usually located at a police department.

The defense strategy options that you may utilize if you’re charged with drunk driving can include questioning whether the officer had reasonable suspicion. You may also be able to bring up any civil rights violations that occurred during or after the traffic stop.

Photo of Attorney Phillip A. Geigle