When a police officer pulls someone over because they suspect them of drunk driving, the officer will follow a specific routine. First, they will talk to the driver to see if they admit to drinking.
Next, they may ask the driver to exit the vehicle to perform a field sobriety test. Depending on how that test goes, the officer may then ask for a chemical breath test. If the driver fails either the field sobriety or the chemical breath test, then the police officer may arrest them. They could also arrest someone for refusing a chemical test if they have probable cause to suspect chemical impairment.
Police officers often already have a suspicion of chemical impairment when they pull a driver over. Why, then, is the field sobriety test an important part of the drunk driving traffic stop procedure?
An officer needs probable cause to ask for a chemical breath test
State law requires that drivers submit to chemical breath tests if a police officer has probable cause to suspect the driver is impaired. One questionable traffic maneuver on its own won’t be enough, but if you combine that with slurred speech when answering questions or abysmal performance on a field sobriety test, the officer can use that combination of factors as probable cause to demand chemical testing.
Your performance on a field sobriety test may be what gives the officer grounds to demand a chemical test during the traffic stop. It will also give them more evidence to recount the courts when they testify at trial should you end up arrested on suspicion of impaired driving.
Learning more about the rules that govern drunk driving charges can help you make safer decisions on the road. They can also help you understand your defense options.