Per se or Prima Facie?
Per se and Prima Facie are terms that are kicked around in law books, legislation, and laws, yet most people don’t have any understanding of what they mean or why they are important. They should.
A Per se standard or rule is absolute. To exceed a Per se BAC limit or speed limit is a violation of the law, no exceptions (for all practical purposes). To have a blood alcohol limit of .08 percent or higher is a clear cut violation of the law, because this is a Per se law. The same is true for exceeding most Interstate highway speed limits, because these are “absolute” speed limits, i.e. Per se speed limits. In the first instance it does not matter if the defendant can perform mental and physical gymnastics, shows no sign of impairment, and was driving competently. If his BAC is over .08 percent he is guilty of violating the law. This violation will stand even if the defendant cannot be shown to have been impaired or incapable of driving safely. Note, violating a .08 BAC law is not the same as being convicted of drunk driving. When it comes to Per se speed limits, exceeding the limit by one mile per hour is a clear violation of the law, regardless of the reason or circumstance, including passing or descending a steep hill.
Prima Facie laws and standards introduce an element of “reasonableness” or rationality into the law. If a Prima Facie speed limit is exceeded a law enforcement officer has cause to stop the driver and issue a citation for violating the speed limit. However, if the defendant can show that she was driving safely and her actions were prudent, and the prosecution can’t refute her claims, the charges should be dismissed.
Enforcement agencies and the courts typically prefer Per se laws. They are easy to enforce and easy to judge. Defendants generally prefer Prima Facie laws because there must be evidence of potentially harmful or irresponsible behavior to merit a conviction. Many states have a mixture of Per se and Prima Facie speed limits. (Almost all BAC laws are Per se laws). If you are ever confronted with defending a traffic ticket it will be well worth your time to determine whether this is a Per se or Prima Facie law.