The Alabama law for impaired driving is broad. Alabama Code § 32-5A191 allows law enforcement to arrest drivers for impaired driving even if they do not have more than the legal limit of alcohol in their blood. Even if a driver’s blood alcohol content is 0.00%, if he or she has used any substance that could impair mind or body to the point that it affects safe driving, the officer can make an arrest.
“Any substance” naturally includes illegal drugs, but it may also include prescription and over-the-counter medications. However, it may be more difficult to prove a DUI involving drugs as a DUI involving alcohol.
Probable cause
Law enforcement must have a reason to pull the driver over in the first place. A driver who is following traffic laws and not displaying any unsafe behaviors should not be a target of police attention.
Reasonable suspicion
Law enforcement cannot just search the vehicle looking for proof that the driver has taken a substance that would impair driving. Drugs that are visible in the vehicle may provide reasonable suspicion. If the officer requests permission to search the vehicle and the driver gives it, then the search is legal. The same applies if the officer obtains a warrant.
Evidence
Before convicting someone of driving under the influence, the judge should require the prosecution to provide evidence not only that the driver took a substance that can cause impairment, but also that it actually caused impairment. This can be challenging without a breath testing device that positively identifies levels of impairment for most medications. A chemical test may reveal the presence of some illegal drugs but would not be effective if a person has merely taken prescription medication according to instructions on the bottle.
Other factors
Even if the officer has probable cause, reasonable suspicion and evidence, there may be procedural errors or other issues that may become part of a strong defense. It is always important to investigate all the circumstances carefully when crafting a defense strategy.