You may admit that you had a couple of drinks before you drove home, but remain confident that your blood alcohol concentration is not at or above .08 percent, which is the legal limit here in Pennsylvania. When you submit to the breath test, the results prove you right. So, why did the police officer still place you under arrest on suspicion of driving under the influence of alcohol?
Thanks to movies and television, many people believe that as long as the results of a breath test don't show legal intoxication (a reading of .08 or above), they can't be arrested for DUI. However, that test only constitutes part of the equation when it comes establishing probable cause for an arrest.
Remember when you admitted to the officer that you had a couple of drinks? That admission could work against you during a DUI stop. Your demeanor may also play a part. Whether you exhibit jovial behavior or combative behavior, it could provide the officer with another step toward probable cause for an arrest.
In addition, whatever driving behavior you exhibited that prompted the traffic stop in the first place may give the officer a reasonable suspicion of impairment. Nowadays, officers usually have dashboard and/or body cameras that provide a visual record of these behaviors that may end up as evidence in court.
Field sobriety tests
Police officers often use these tests to bolster probable cause to make a DUI arrest. The presumption is that if you "fail" these tests, which are designed to test your mental and physiological impairment, you are too impaired to drive. At least one camera is usually recording during field sobriety tests as well.
Challenging the evidence
In many cases, someone charged with DUI will challenge the results of the breath test. In your case, that test did not indicate that you were legally drunk, which works in your favor. The rest of the so-called evidence of your alleged intoxication now comes under scrutiny. Nearly all of the other evidence requires some sort of supposition on the part of the arresting officer.
If you had a bad day, you may not be polite, but being rude does not necessarily indicate impairment. You may be a naturally bubbly person. Those "couple" of drinks that you had may not be enough to diminish your driving capabilities. Field sobriety tests are notoriously inaccurate since numerous physical conditions can cause someone to fail them, even if that person has not had even one alcoholic beverage before getting behind the wheel.
If you find yourself facing a DUI charge, it may be in your best interests to exercise your right to challenge the alleged evidence of your intoxication.