Many DUI / DWI arrests involve roadside breath tests, which are designed to measure a driver’s blood alcohol content (BAC).

The central factor in a Driving Under the Influence arrest and subsequent drunk driving prosecution is the motorist’s alcohol level at the time of driving, not at the police station, where many BAC tests are performed. Stationhouse breath or blood test results are only relevant to the extent that they allow someone to look back in time, and draw inferences about the motorist’s blood or breath alcohol level at the earlier time of driving.

As more and more time passes from the time of drinking to the time of driving to the time of testing, the BAC at the time of driving becomes increasingly hard to accurately pinpoint. Thus, in an attempt to develop evidence closer in time to the time of driving, roadside breath testing has gained popularity.

DUI / DWI criminal defense attorneys have been dealing with roadside breath testing for years.
Preliminary breath tests (PBTs) are merely screening tests given to support the officer’s decision to make an arrest. A PBT tests the breath for the presence or absence of alcohol. In New York, the most common type of breath screening test is the Alco-Sensor test. The Alco-Sensor is a portable, handheld device used by many officers on patrol to establish probable cause for a DUI / DWI arrest.

Although a PBT does generate a numerical test result, evidence of the administration of an Alco-Sensor test or the result of an Alco-Sensor test is inadmissible at a trial in a New York State court. Generally, the results are only reliable for determining the presence or absence of alcohol in a person’s breath.

If you are stopped for suspicion of drunk driving, you are under no obligation to submit to a PBT unless you have been in an accident or violated the Vehicle and Traffic Law. Refusal of a valid request to submit to a PBT is a traffic infraction without any driver’s license consequences.
It is therefore vital anyone arrested for a DUI / DWI, drunk driving, or any drinking and driving offense, contact a criminal defense attorney who is well-versed in the issues involving roadside breath testing.