How Do the Police Determine a Drug-Related Charge?
Interviewer: What system has the police developed, right or wrong, to evaluate people? How do they do it? What occurs out in the field during their evaluations?
The Police Utilize the Standard Field Sobriety Tests, Which Were Developed to Detect Alcohol, Not Drug Impairment
Kevin: The officer will utilize field sobriety tests prior to arrest. The field sobriety tests typically used are the one-leg stand test, walk and turn test, and the HGN test, which is also known as the horizontal gaze nystagmus test.
However, those tests were devised by the National Highway Traffic Safety Administration to determine if a person is under the influence of alcohol, not drugs.
There are some programs established by the National Highway Traffic Safety Administration which teach officers to use those field sobriety tests to determine if somebody is under the influence of particular drugs. But, there are no published studies in the United States that actually show that those field sobriety tests relate to drug intoxication.
Because of the Amount of Different Drugs and the Seven Categories They Fall under, Field Sobriety Tests Cannot Be an Adequate Measure of Drug Impairment
Certainly, there are a number of different drugs that people can consume. These field sobriety tests will never be able to be studied in relation to every type of drug that can be consumed, or every type of drug category.
There are seven drug categories that drugs will fall into. They are central nervous system depressant, central nervous system stimulant, hallucinogen, dissociative anesthetic, narcotic analgesic, inhalants and cannabis (marijuana).
You have to think about it in a scientific way and really analyze whether these two balance tests and the HGN test, really have any scientific validity in relation to each one of these seven broad drug categories.
There are no extensive scientific studies to show that field sobriety tests have a predictive ability to determine if somebody is under the influence of drugs.