A Look Around the Country at the Admissibility of Evidence in Drugged Driving Cases

Last week I wrote about studies examining the prevalence of driving with drugs in one’s system. Research has shown that an increasing number of drivers have detectable drugs in their symptoms. What we don’t yet know is how many of those drivers are impaired by drugs and whether the incidence of drug-impaired driving is increasing.

We do know, of course, that drug-impaired driving is dangerous. Policy-makers in North Carolina and elsewhere have attempted to combat the problem by enacting zero-drug-tolerance laws and provisions that prohibit driving with a threshold of a drug or its metabolites in one’s body. And law enforcement officers across the country have created detection protocols that are geared specifically toward the drug-impaired driver rather than a driver impaired by alcohol.

Notwithstanding these measures, drug-impaired driving continues to be prosecuted in North Carolina and other states under statutory schemes and law enforcement protocol that were primarily written and developed to deter, detect and punish alcohol-impaired driving.

Courts across the country are increasingly being required to consider how those schemes and that protocol apply to drug-impaired driving prosecutions. This post will summarize recent court rulings on the admissibility in drugged driving prosecutions of (1) evidence regarding a defendant’s performance on field sobriety tests, (2) testimony about the effects of certain drugs, and (3) lay opinion testimony about the person’s impairment.  It will also review recent opinions regarding the quantum of proof necessary to establish drug-impaired driving. It will conclude with a case that demonstrates why drugged driving is a matter of serious concern.

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