To pull someone over on suspicion of driving while intoxicated (DWI), police officers need reasonable suspicion. This means that they have valid grounds to believe that something is off with the driver. For example, the driver may be speeding, crossing the centerline or engaging in other potentially hazardous behaviors.
Reasonable suspicion alone, however, is not enough to arrest and charge someone with DWI. To make an arrest, police officers need probable cause. This means that they need hard evidence that indicates the driver is impaired.
One way police officers can obtain this is by administering a breathalyzer test. This test measures the blood alcohol content (BAC) of the driver. A high reading can give officers the probable cause required to make an arrest. Nonetheless, breathalyzer tests can be inaccurate for the following reasons:
The accuracy of breathalyzer tests can be questionable
Very few technologies are foolproof, and this includes breathalyzer tests. A breathalyzer test may give an inaccurate reading if:
- It has not been properly calibrated. Breathalyzers must be calibrated appropriately and repaired or disposed of when necessary. Calibration and repairs can only be conducted by approved individuals. An improperly calibrated test can give inaccurate results.
- Improper administration of the test. Officers must administer the test properly. For example, they should wait 15 minutes before administering the test. This prevents residue alcohol from the mouth from being registered instead of BAC.
While breathalyzers are relatively accurate, they can be wrong. To challenge the evidence against you in your case, it will help to seek some legal guidance as soon as you can.