A preliminary alcohol screening (PAS) device is a tool used by law enforcement officers during drunk driving investigations. This portable breath test device allows officers to conduct a quick field assessment of a driver’s blood alcohol concentration (BAC).
Unlike the stationary breath test machines found at police stations, PAS devices offer immediate results and are primarily used during traffic stops. Understanding the role of a PAS device and how it differs from stationary breath test machines is important, especially for drivers who might encounter such checks.
Differences from stationary breath test machines
The primary distinction between a PAS device and a stationary breath test machine is their accuracy and purpose. PAS devices are less accurate and are generally used for preliminary screening to establish probable cause for an arrest rather than for definitive legal evidence.
Stationary machines used post-arrest at police stations are designed to provide highly accurate BAC readings admissible in court. These machines undergo regular calibration and maintenance to ensure their precision. Results from these are a bit harder to challenge in court because of these machines’ calibration records and dependability.
The role in drunk driving cases
PAS devices serve as an initial assessment tool. If an officer suspects a driver is under the influence, a PAS device can quickly indicate whether the driver’s BAC is potentially over the legal limit. This is often used in conjunction with standardized field sobriety tests to develop probable cause for an arrest.
While the results from a PAS device alone aren’t used as evidence in court, they are crucial in establishing the need for further testing with a stationary breath test machine. Results from the larger breath test machine can provide the legally admissible BAC level required for prosecution.
Anyone facing drunk driving charges should work with someone who can evaluate the evidence against them. This information can help them to determine what type of defense strategy to use. Not every testing scenario is the same and it may be possible to challenge evidence under certain circumstances.
