Today St. Charles DWI lawyer Todd Ryan continues coverage of the Standard Field Sobriety Tests (SFSTs). Last week, we covered introduced the SFSTs and looked at the Horizontal Gaze Nystagmustest specifically. The SFSTs play an important role in many St. Charles DWI arrests, and understanding them is essential to properly defending DWI cases.
The SFSTs were originally developed to detect drivers whose BAC was at or above .10%. Many states, Missouri included, have since lowered the legal limit (or the presumptive limit) to .08%. Since 1975, there have been subsequent efforts undertaken to validate the SFSTs against the lower BAC limit. It’s important for all drivers to remember that the results of any SFST can be successfully challenged several different ways. When using the SFSTs to investigate a driver, the officer is far more likely to report a false positive than a false negative.
The “Walk and Turn” was part of the original 1975 study. In Missouri, the Walk and Turn is listed second on the officer’s Alcohol Influence Report (AIR). The AIR gives the officer a checkbox, and a diagram showing each of the steps the driver is to take. The officer uses the AIR to record his or her observations.
The Walk and Turn is a divided attention test with an Instruction portion and a Walking portion. During the Instruction part of the test, the driver’s attention will be divided between balancing in the starting position and listening to the officer’s further instructions. During the test, the officer is looking for at least two of the eight possible clues. The Walk and Turn test is challenged frequently in Missouri.