It is illegal for people to drive when they notice that alcohol has affected their abilities. It is also illegal to operate a motor vehicle once a driver’s blood alcohol concentration (BAC) reaches 0.08%.
Police officers who suspect people of chemical intoxication often begin looking for evidence to justify arresting them. They also need to gather evidence that can help a prosecutor prove those allegations in a criminal trial. Tests are an important part of drunk driving enforcement efforts.
What tests do police officers frequently administer when evaluating people for intoxication?
Field sobriety tests
Sometimes, officers have a vague suspicion of intoxication but do not have probable cause to arrest someone. They may ask a driver to exit their vehicle and perform a series of field sobriety tests. Typically, officers perform three standardized field sobriety tests. Officers ask people to perform the walk-and-turn test, the one-leg stand test and the horizontal gaze nystagmus test.
While these tests can potentially produce false positive results, they can also give officers the probable cause necessary to arrest a driver and then request a chemical test. Technically, drivers can refuse to perform field sobriety tests without putting themselves at risk of arrest.
Breath tests
It is possible for an officer to perform a minimally invasive test on the side of the road to evaluate a driver’s BAC. By having them blow into a device, officers can obtain a quick reading that may show that the driver is over the legal limit for their BAC.
Provided that the police officer has probable cause to arrest a driver, refusing a chemical test can complicate the situation. Drivers may face additional consequences for violating the implied consent statute by refusing post-arrest testing.
The good news for those who may have failed breath tests or field sobriety tests is that both types of testing are notorious for producing false positives. They may be able to show that they were not over the legal limit by presenting medical evidence or that there could have been issues with the device used to perform a breath test.
Understanding the field sobriety testing and chemical testing that can occur prior to drunk driving charges may help people protect themselves against unnecessary prosecution. Even those who fail the tests administered by the police may be able to avoid a conviction with the right criminal defense strategy.
