Beginning in late 1975 extensive research studies were sponsored by the Department of Transportation through a contract with the Southern California Research Institute to determine which roadside field sobriety tests were the “most” accurate. There were 3 reports generated. A 1977 Lab Report, a 1981 Lab and Field Report, and Field Reports conducted during 1983 in Maryland, D.C., VA, and NC.
The most reliable predictors of a person with a 0.10 blood alcohol level were the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn (WAT), and the One-Leg Stand (OLS). Their individual accuracy was HGN 77%, WAT 68%, and OLS 65%. Between 1995 and 1998, three validation studies were conducted, one in Colorado, one in Florida, and one in San Diego.
Here’s the problem with the tests. Simply stated, if the tests are not done the way they were designed to be performed, then they are pretty much worthless in predicting anything. Junk in, Junk out. If the input gained from an officer’s observations of abbreviated tests, poorly instructed tests, or just plain aborted tests, then what you put in is what you get out…junk, phony field tests that don’t indicate anything reliable.
Robert La Pier, former field commander of the Idaho State Police, trained me in the NHTSA and International Association of Chiefs of Police (IACP) DUI detection and Standardized Field Sobriety Testing in Los Angeles in 2005. I know how to do these tests right and I’ve never seen them done right by any law enforcement officer.
The CHP field manual for the FST’s indicates that the HGN should take about 84 seconds to complete. In all of the mobile videos I’ve reviewed in recent years I’ve yet to see an officer spend more than 22 seconds on this test, yet in their reports, they claim to find all of the impairment clues in as little as 12 seconds. That’s just plain impossible to do.
The tests are phony, the reports of the tests are absurdly inaccurate, yet District Attorneys and Judges nonetheless believe that these officers know what they’re doing and that they report the results accurately.
When an officer gets someone out of a vehicle and tells them, “what I need you to do” or “I just want to make sure you’re OK to drive” or “I’ve just got a couple of tests I’d like you to do”, Just say no. Ask the officer if these are required and he’ll dance around that question and likely never answer it.
The answer is no, they are not required because everything you say or do can and will be used against you in a court of law
…just repeat those words, give yourself the Miranda advisement, and tell the officer you respectfully decline his offer.