The Standardized Field Sobriety Testing Scam

Posted On January 29, 2024 Charles Ramsay

Did you know that the standard field sobriety tests (SFSTs) that officers use to determine probable cause for arrest are basically designed for you to fail?

Tests such as the one-legged stand, walk and turn, and the horizontal gaze nystagmus are based on a report funded by the National Highway Traffic Safety Association (NHTSA). Talk about a conflict of interest!

In 1998, NHTSA hired a firm called Anacapa Science, Inc. to try to validate the bogus tests known as SFSTs.  

The report made extravagant claims about the accuracy of the SFSTs, claiming that they were “extremely accurate” at predicting if someone’s BAC was >0.08%. 

They went so far as to say that the SFSTs were up to 94% accurate! Reading the report, you’d wonder why we even need breath or blood testing at all. 

The report concluded that, on average, officers were able to predict a person's BAC within 0.005%! Now that’s pretty amazing! Unfortunately, the authors downplayed the false positive rates. 

False positives are the number of people who were below 0.08% BAC but got arrested anyway. There was a 29% false positive rate in the report!

Put another way, officers guessed wrong in 24 cases. They guessed that 24 of the 83 sober subjects were actually greater than 0.08% BAC (24/83 = 29%).

Of the predictions that the officers got right (estimating >0.08% BAC), the average subject had a BAC of 0.15%! It’s not so hard to predict that someone is >0.08% if they’re nearly double that level! 

The report also doesn’t mention if the officers wrote down their predictions before or after they gave subjects a portable breath test (PBT). If the officers looked at the PBT before making their prediction, it’s much more likely that they’d get a correct estimate from the final breath or blood test at the police station.

This is just one of the many problems with SFSTs. We’ve written about the problems with SFSTs in the past about the problems with SFSTs and we’ll continue to do so.


If you’ve been accused of a DWI based on faulty SFSTs, call us today. You need a firm that understands the lack of science behind these tests. At Ramsay Law, we have the only board-certified DWI defense in the state (recognized by the American Bar Association, not the MSBA). 


We look at all the data to ensure you get the best defense possible.

Call 651-604-0000 to talk with us today.