How Do Police Test for Drugs in DUI Cases?

Unlike driving under the influence (DUI) of alcohol, which is typically proven with a straightforward Blood Alcohol Concentration (BAC) measurement, establishing drug impairment is rarely so simple. Law enforcement officers employ various strategies, including detailed observations and specialized testing, to build a case. Prosecutors must present compelling evidence that the driver’s ability to operate a motor vehicle safely was compromised or that certain illegal substances were present in their system. Please continue reading to learn how police test for drugs in DUI cases and how a knowledgeable Tempe DUI-Drugs Lawyer can help combat your charges at every turn.  

How Do Police Determine Drug Impariment in DUI Cases?

In Arizona, police officers who have been certified as Drug Recognition Experts (DREs) may seek to provide an “expert” opinion regarding a driver’s impairment by illegal substances. To arrive at this determination, a DRW follows a strict 12-step drug evaluation protocol. This process commences with a breath alcohol test and an interview with the arresting officer. The DRE then carries out several assessments, including a preliminary medical screening, a thorough eye examination for involuntary jerking (HGN and VGN), and a set of psychological tests requiring divided attention, such as the Walk and Turn and the One Leg Stand. 

Next, the DRE measures the Driver’s vital signs, inspects their pupils under various light conditions during a dark room procedure, and evaluates muscle tone and possible injection marks. All these observations are meticulously recorded, and the DRE attempts to confirm their findings against the motorist’s own statements. Ultimately, the DRE forms an opinion on the category of drugs affecting the driver based on a pattern of indicators, which is then intended to be verified by laboratory analyses of the driver’s blood, saliva, or urine. 

What is Arizona’s “Per Se” Drug DUI Law?

Arizona enforces strict rules for specific substances. Operating a motor vehicle with any trace of certain illicit substances can result in criminal charges. Establishing impairment is not always necessary for this to apply to particularly controlled substances. 

Furthermore, declining drug test results will result in immediate penalties. The implied consent law presumes that drivers have agreed to such testing by getting behind the wheel. A refusal can trigger the suspension of your driving privileges and may be used against you as evidence in court. 

At The Weingart Firm, PLLC, we are prepared to help you navigate your charges and protect your rights during this difficult time. Drug DUI charges carry harsh penalties that can haunt you for a long time. Connect with us today to schedule a free consultation.