How Do Squad Car Lights Affect Field Sobriety Tests?

| Feb 17, 2019 |

How Do Squad Car Lights Affect Field Sobriety Tests?Prior to the FSTs, many officers make some accommodations. They normally do not require people with prosthetic legs to perform the one-leg stand test and they sometimes give women the chance to take off high-heel shoes prior to the walk-and-turn test. If officers deny needed accommodations, the test results are skewed.

But officers almost never turn off their flashing squad car lights during DWI stops. Additionally, the almost never ask questions like “Do those lights bother you?” They keep the lights flashing and expect drivers to perfectly perform all three approved field sobriety tests. However, if there are flashing lights in the background, they affect all three tests.

The Effect of Flashing Lights

Today’s police strobe lights are nothing like the simple ones on top of Sargent Joe Friday’s car in Dragnet. An entire generation of readers probably have no idea what that reference is about. Today’s squad car lights are designed to disorient suspects. This disorienting effect causes some issues.

These lights sometimes cause flicker vertigo. People who suffer from this condition experience epilepsy-type symptoms, including rapid and uncontrollable eye movements. These individuals may also experience muscle rigidity and lose control of fine motor skills. These kinds of lights may also trigger ocular migraines. These people see things like shooting stars, flashing lights, zig-zagging lines, or even psychedelic images. These symptoms usually dissipate in about a half hour, but that’s small comfort for people who must perform field tests immediately.

Sometimes, the effect is more subjective. To many people, flashing lights are just scary. That’s why so many haunted houses have strobe lights.

Squad Car Lights and the FSTs

Both flicker vertigo and ocular migraines directly affect all three of the approved Field Sobriety Tests. Furthermore, most people are already scared during DWI stops. The flashing lights just make things worse.

· OLS/WAT: Both the one-leg stand and walk-and-turn have physical components. If your vision and muscles are impaired, it’s impossible to satisfactorily complete these tests. Many times, ocular migraines and flicker vertigo are rather subtle, so the defendants themselves may not know the effects.

· Horizontal Gaze Nystagmus: In this test, officers look for involuntary pupil movements at certain angles. If the defendant’s eyes are already moving uncontrollably, these test results are arguably meritless.

Many Parker County prosecutors are completely unprepared to deal with the scientific and medical aspects of squad car lights. Furthermore, a line of questioning like this gives a defense attorney additional credibility in the minds of jurors.

During DWI field tests, the deck is stacked in favor of officers. For a free consultation with an experienced criminal defense attorney in Weatherford, contact Herreth Law. We are available for assistance 24/7/365.