Field Sobriety Tests

New Jersey police often ask drivers suspected of a New Jersey DWI / DUI to take a field sobriety test before they are placed under arrest. Many drivers believe that they can avoid arrest by “passing” a field sobriety test, but that’s rarely the case, because these tests are designed to be failed. They exist solely to create probable cause to make an arrest and to generate evidence for a drunk driving prosecution.

Field sobriety tests are a key piece of evidence in a prosecutor’s NJ DWI / DUI case, but many drivers don’t realize that they can also be very useful to the defense. Prosecutors will attempt to show that any variation between the manner in which the officer explained the tests and the way in which the subject performed the tests is proof of mental and physical impairment. However, New Jersey DWI defense lawyer Evan Levow may be able to use the same field sobriety tests to show that the driver was not intoxicated.

Three tests have been standardized by the National Highway Traffic Safety Administration (NHTSA). These are the horizontal gaze nystagmus test, the walk and turn test, and the one leg stand test. These tests are standardized because they have precise instructions to follow, and an objective scoring system.

These tests include the Rhomberg balance test, the finger-to-nose test, reciting the alphabet, the hand-pat test, and the finger-tap test.

New Jersey DWI cases are prosecuted under two different theories – driving under the influence, which is focused on whether the driver was mentally and physically impaired, and the “per se” allegation, which concentrates on whether the driver’s blood alcohol content (BAC) was .08 percent or greater.

Field sobriety tests are used as circumstantial evidence to support the allegation of driving under the influence. Field sobriety tests are divided attention exercises, meaning they are designed to force drivers to simultaneously focus on two tasks. Although field sobriety tests are optional, most officers don’t advise drivers of that fact.

The driver’s alleged physical and mental impairment is at the heart of every DWI / DUI prosecution. Forensic experts agree that alcohol consumption can cause both mental and physical impairment, but mental impairment always occurs first.

Individuals with a high tolerance for alcohol can sometimes mask signs of physical impairment, but it is impossible to disguise signs of mental impairment. Therefore, if the driver displayed physical impairment, but not mental impairment, any physical problems must have stemmed from a source other than alcohol.

Any number of issues that have nothing to do with alcohol intoxication can cause physical impairment. Injuries or other physical disabilities can hinder a driver’s ability to perform on field sobriety tests. Fatigue can also affect the driver’s performance, as can nervousness. Wearing shoes with heels may affect testing. Persons more than 50 pounds overweight should not be administered the testing, and persons over 65 may have poor balance and should not be caused to perform the exercises.

Ultimately, all field sobriety tests, even those standardized by the NHTSA, are highly subjective and can be effectively challenged. Regardless of how the driver performed on a field sobriety test, an experienced New Jersey drunk driving defense lawyer can argue that performance problems were caused by factors unrelated to alcohol use.

Please call us today to speak with a skilled NJ DWI lawyer at Levow DWI Law. Call now for a free New Jersey DWI consultation.