Montgomery County, Texas law enforcement is aggressively prioritizing catching those driving under the influence of drugs – with particular attention to marijuana and opiates. In addition to typical standardized field sobriety testing, officers will also occasionally utilize the Drug Recognition Exam (DRE). Defense attorneys have long sounded the alarm with horror stories about these examinations. In 2024, Alsbrooks Law defended a Minnesota truck driver without a trace of any intoxicant in his blood – yet a supposed expert used the DRE to falsely allege the client was under the influence of opiates.
While DRE’s might sound scientific, they’ve been heavily criticized by medical experts, legal scholars, and even courts in certain states, for their lack of reliability and scientific foundation.
What Is a Drug Recognition Exam (DRE)?
A Drug Recognition Exam is a 12-step procedure performed by a police officer certified as a Drug Recognition Expert. These exams involve checking pulse rates, measuring pupil size, conducting balance and coordination tests, and asking about recent drug use. Based on these observations, the officer makes a subjective judgment about whether the driver is impaired and what drug category might be involved.
What the Research Says About DRE Reliability
Despite their official-sounding title, Drug Recognition Exams have been the subject of significant academic and legal criticism:
1. Flawed Methodology and Confirmation Bias
One of the earliest evaluations of the DRE program, conducted by the National Highway Traffic Safety Administration in conjunction with the Los Angeles Police Department (Compton, 1986), was criticized for serious methodological flaws. Officers often knew what drugs suspects had taken prior to performing the exams, undermining the objectivity of the results.
2. Poor Correlation Between Signs and Actual Impairment
Multiple peer-reviewed studies have shown that many of the physical signs relied upon in DREs — such as pupil size, pulse rate, and eye movement — can be caused by factors unrelated to drug use. A 1999 study by Heustis et al. found that physiological signs of marijuana use didn’t consistently correlate with impairment, while a 2005 study by Papafotiou, Carter, & Stough revealed that Standardized Field Sobriety Tests (SFSTs), which share many elements with DREs, had poor sensitivity for detecting marijuana impairment.
3. Lack of Scientific Consensus
Experts writing in the Journal of Analytical Toxicology and organizations like the ACLU and the National Association of Criminal Defense Lawyers (NACDL) have labeled DRE protocols as pseudoscientific and inherently subjective. These critics point out that no double-blind, peer-reviewed studies conclusively validate the accuracy of DRE conclusions in real-world traffic stops.
4. Legal Challenges in Court
Courts in several states have also begun scrutinizing DRE testimony. In State v. Sampson (Oregon Court of Appeals), the court questioned the scientific reliability of DRE evidence, setting a precedent for its limited admissibility without proper foundational proof.
How a Texas DWI Defense Attorney Can Help
If you’ve been charged with DWI based on a Drug Recognition Exam in Texas, you don’t have to accept flawed science as evidence against you. At Alsbrooks Law, serving Montgomery County and all of East Texas, we carefully dissect the weaknesses in DRE-based arrests, challenge the officer’s conclusions, and expose the lack of scientific foundation behind these evaluations.
Contact us today for a free consultation and find out how we can help protect your rights.