Introduction

Driving under the influence (DUI) and driving under the influence of drugs (DUID) are significant public safety concerns that lawmakers and law enforcement agencies work tirelessly to address. While the need to deter and punish intoxicated drivers is undeniable, the per se theory of prosecution has sparked a debate about whether it adequately addresses the issue of impairment. Critics argue that per se prosecutions focus on a specific number rather than the actual harm: being too impaired to drive. In this blog post, we will explore the per se theory and its implications on DUI and DUID cases.

Per Se Theory Explained

Per se DUI and DUID laws are based on the principle that a driver is considered intoxicated if their blood alcohol concentration (BAC) or the presence of a specific drug exceeds a predetermined threshold, regardless of their actual level of impairment. In the United States, the legal BAC limit for drivers is 0.08% for adults in a non-school, non-CDL vehicle in most states. For DUID cases, the legal limits for drugs vary by state and substance.

The Controversy: A Focus on Numbers, Not Impairment

Critics argue that per se laws are a form of “legal cheating” because they allow for convictions without the need to prove impairment. By relying solely on a predetermined number, per se laws bypass the question of whether a driver’s abilities were genuinely affected by alcohol or drugs. This approach can lead to the conviction of individuals who may not have been too impaired to drive safely.
Moreover, individual tolerance and metabolism can significantly impact how alcohol or drugs affect a person. Some drivers may be impaired at a BAC or drug concentration below the legal limit, while others may still be capable of driving safely even with a BAC or drug concentration above the threshold.

The Perceived Harm: The Disconnect Between Per Se Limits and Actual Impairment

The primary concern with per se laws is that they do not punish the perceived harm of DUI and DUID offenses: being too impaired to drive. Instead, per se laws create an arbitrary standard that may not accurately reflect an individual’s ability to operate a vehicle safely. This approach can result in the conviction of drivers who pose little threat to public safety while failing to address those who may be impaired but do not meet the per se criteria.

Conclusion

While per se DUI and DUID laws provide a seemingly objective standard for determining intoxication, they may not adequately address the issue of impairment. By focusing solely on a predetermined number, these laws can lead to convictions without adequately addressing the perceived harm of intoxicated driving. A more comprehensive approach that evaluates an individual’s actual impairment would better serve the goals of public safety and justice.

Justin McShane

PA DUI attorney Justin J. McShane is the President/CEO of The McShane Firm, LLC - Pennsylvania's top criminal law and DUI law firm. He is the highest rated DUI attorney in PA as rated by Avvo.com. Justin McShane is a double Board certified attorney. He is the first and so far the only Pennsylvania attorney to achieve American Bar Association recognized board certification in DUI defense from the National College for DUI Defense, Inc. He is also a Board Certified Criminal Trial Advocate by the National Board of Trial Advocacy, a Pennsylvania Supreme Court Approved Agency.