Drug-impaired driving is risky behavior. The fact that many Americans fail to recognize that risk makes it all the more dangerous — especially when they decide to get behind the wheel while under the influence of drugs.
Making matters worse is the daunting challenge facing those in the criminal justice system tasked with detecting and prosecuting drivers impaired by drugs other than alcohol.
For alcohol impairment, years of robust data have reliably established specific, detectable levels of blood alcohol associated with impairment. In contrast, for other widely available drugs, both legal and illicit, to date the data are insufficient to establish enforceable impairment markers. For instance, as yet there are no reliable markers to definitely establish impairment by THC and other marijuana components.
For the criminal justice system, developing effective policies, practices, and standards to fight drug-impaired driving means first building a firm foundation of priority research needs for law enforcement, forensic toxicology, prosecuting agencies, and practitioners.
Taking a Multi-Disciplinary Approach to Ranking Research Needs
Toward that end, NIJ held a workshop in which expert law enforcement officers, toxicologists, and prosecution officials identified and ranked top needs for relevant research. Researchers from the RAND Corporation (RAND) and RTI International (RTI) facilitated the workshop, part of the NIJ-sponsored Priority Criminal Justice Needs Initiative.
Select examples of high-priority justice system needs identified by the expert panel are:
For law enforcement
- For each agency, identifying the right number of officers with specialized training in identifying drug impairment.
- Developing more observational tests for the standard field sobriety battery.
- Developing training to boost the confidence of law enforcement officers called to testify in drug cases.
For forensic toxicologists
- Identifying gaps in funding and other resources for forensic toxicology labs to meet capability requirements and demand.
- Establishing training for toxicologists on interpreting test results in driving under the influence of drugs cases.
For prosecutors
- Providing more access to training, given that drug-impairment cases are among the most technical and difficult to litigate.
- Identifying best practices for dealing with drivers’ refusal of impairment tests.
(See complete list of priority needs in “The 13 Top-Tier Needs”.)
The Challenge of Identifying Drug-Impaired Driving
The panel emphasized the primary importance of establishing a suspect’s drug impairment, even absent a means to detect the amount of drug in the suspect’s system, according to the workshop panel’s report. Tools commonly deployed to assess drug impairment, and key benefits and drawbacks of those tools, include the following:
Evidentiary Challenges in Drug-Impaired Driving Cases
The incidence of drug-impaired driving has risen in recent years, even as more states moved to legalize cannabis for recreational and medicinal purposes in several states, according to the research report. In 2017, 12.8 million individuals drove under the influence of drugs alone, up 9% from the previous year, according to the federal Substance Abuse and Mental Health Services Administration. Cannabis-related impairment is second only to alcohol in impaired-driving statistics. Studies have shown that states that have legalized cannabis use have experienced increases in traffic deaths after the opening of cannabis stores.
Given those trends, new urgency has attended enforcement of laws against drug-impaired driving. But solutions need to be able to withstand evidentiary challenges. In contrast to alcohol, which can be detected in the system up to 12 hours after ingestion, THC, the chemical component of cannabis associated with impairment, can quickly dissipate in the system. Some cannabis elements, on the other hand, are detectable long after any impairment has worn off.
Further complicating enforcement is the absence of any fixed threshold of THC concentration in blood signaling user impairment — unlike the 0.08% blood alcohol level widely accepted as evidence of alcohol impairment. Prosecutors are challenged by the fact that many courts tend to view such tests as evidence of drug use only, and not per se proof of impairment, unless concentrations are very high. “Because of these limitations,” the report said, “observational field tests performed by skilled law enforcement officers who make contact with the suspect are a critical piece of evidence, which, along with chemical tests (that provide corroboration), can support a finding of drug-related impairment.”
Another variable is inconsistent evidentiary standards among the states, with some states adopting certain drug concentrations as evidence of potential impairment, and others taking a zero-tolerance approach — that is, one where any detectable amount of a substance is deemed evidence of impairment.
Three types of training are available for officers to perform observational drug tests: drug recognition expert certification, standardized field sobriety test training, and an advanced roadside impairment test training course developed by the National Highway Traffic Safety Administration. In all three areas, however, admission of evidence in court can be problematic if the officer deviates from protocols.
Conclusion
Signs and symptoms of drug-impaired individuals vary, and proving impairment can be a complex undertaking. Standardized observational tools and chemical tests, however, can yield legally sufficient proof of drug-impaired driving, the report noted. Collaboration across fields is critical to adequate enforcement, as is the education of judge and jury by prosecutors on how to weigh observational and chemical evidence under a totality-of-the-circumstances standard of proof.
Republished courtesy of NIJ.