Police typically use field sobriety tests such as the hand pat test when investigating a suspected drunk driver. However, these ‘tests’ aren’t used to help an officer decide whether to make an arrest – that decision is typically made before the test begins. Field sobriety tests are used solely to create probable cause for an arrest and to generate evidence for a court case. However, it’s possible to successfully challenge the results of the hand pat test and other field sobriety exercises. A Florida criminal defense attorney who concentrates on DUI / DWI cases can develop a strategy to aggressively fight a drinking and driving case.

An officer administering the hand pat test will direct the driver to extend one hand with the palm up, and place the other hand on top with the palm down. The driver must then pat the bottom hand with the top hand, while alternating the top hand’s palm position (facing up/facing down between pats). The driver must count out loud with each pat. The officer is watching for signs that the motorist is impaired, including starting the test too soon, an inability to follow instructions, an inability to count as directed, an inability to pat hands as instructed, and stopping the test before told to do so.

Even though police and prosecutors view a driver’s performance on the hand pat test as evidence of intoxication, that’s not necessarily the case. The hand pat test is extremely subjective, meaning that the results can be interpreted in more than one way. It’s such an unreliable measurement of alcohol intoxication that it isn’t recognized as a standardized field sobriety test by the National Highway Traffic Safety Administration (NHSTA.)

Like many field sobriety tests, the hand pat test relies heavily on physical coordination, which is not an accurate indicator of impairment caused by alcohol intoxication. To see why many field sobriety tests are inherently unfair, it’s helpful to understand how alcohol affects the central nervous system. When an individual drinks alcohol, mental impairment always occurs before physical impairment. If no mental impairment is displayed, any physical impairment must come from a source other than alcohol.

A poor performance on the hand pat test can stem from illness, injury, a nervous-system disorder, or any number of other causes, and doesn’t necessarily support a drunk driving charge.