A large percentage of investigations for DWI will include a battery of tests known as "field sobriety tests.
" These are intended to enable a police officer to determine whether a suspect is guilty of driving while intoxicated without the necessity of using chemical testing such as the breathalyzer or tests of the suspect's blood or urine.
Many drunk-driving convictions are based on the fact that the defendant failed a field sobriety test, despite the fact that these tests have many well-known weaknesses and are considered by some to be unreliable as evidence in a court of law.
The standardized set of field sobriety tests was developed by the National Highway Traffic Safety Administration and released for use across the nation in 1981.
Prior to the implementation of the NHTSA tests, police officers and state troopers had to use their own subjective judgment and rule-of-thumb guidelines to decide whether a suspect was under the influence of alcohol.
The current tests offer a higher degree of uniformity in testing procedures, but they still depend largely on the officer's opinion, rather than on objective scientific measurements.
The three most widely used tests are the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn (WAT), and the One-Leg Stand (OLS).
The HGN involves waving an object such as a pen in front of the suspect's face while watching for irregularities in the motion of the eyes.
The Walk-and-Turn tests the suspect's physical coordination along with the ability to understand and execute directions.
The One-Leg Stand requires the suspect to stand with one leg in the air while counting, while the officer watches for signs of intoxication such as swaying, hopping, using arms to balance and putting the foot down.
While it is true that being intoxicated will typically make it more difficult for a driver to pass any of these tests, other factors can cause a person to fail.
For example, someone who is significantly overweight, out of shape or who has poor physical coordination may be unable to pass the One-Leg Stand or the Walk and Turn, while others have been known to fail the Horizontal Gaze Nystagmus as a result of glaring police lights, passing headlights and having a flashlight pointed directly in the face.
Other issues which may compromise FST results include bad weather, poor roadside conditions such as gravel on the shoulder, nervousness caused by intimidating behavior from the police officer and the stress of being investigated for DWI, as well as the suspect's footwear.
If you have been charged with DWI after failing the FSTs and believe that the test results were prejudiced against you, it may be possible for you to avoid a conviction if you retain a skilled attorney to represent you in court.
" These are intended to enable a police officer to determine whether a suspect is guilty of driving while intoxicated without the necessity of using chemical testing such as the breathalyzer or tests of the suspect's blood or urine.
Many drunk-driving convictions are based on the fact that the defendant failed a field sobriety test, despite the fact that these tests have many well-known weaknesses and are considered by some to be unreliable as evidence in a court of law.
The standardized set of field sobriety tests was developed by the National Highway Traffic Safety Administration and released for use across the nation in 1981.
Prior to the implementation of the NHTSA tests, police officers and state troopers had to use their own subjective judgment and rule-of-thumb guidelines to decide whether a suspect was under the influence of alcohol.
The current tests offer a higher degree of uniformity in testing procedures, but they still depend largely on the officer's opinion, rather than on objective scientific measurements.
The three most widely used tests are the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn (WAT), and the One-Leg Stand (OLS).
The HGN involves waving an object such as a pen in front of the suspect's face while watching for irregularities in the motion of the eyes.
The Walk-and-Turn tests the suspect's physical coordination along with the ability to understand and execute directions.
The One-Leg Stand requires the suspect to stand with one leg in the air while counting, while the officer watches for signs of intoxication such as swaying, hopping, using arms to balance and putting the foot down.
While it is true that being intoxicated will typically make it more difficult for a driver to pass any of these tests, other factors can cause a person to fail.
For example, someone who is significantly overweight, out of shape or who has poor physical coordination may be unable to pass the One-Leg Stand or the Walk and Turn, while others have been known to fail the Horizontal Gaze Nystagmus as a result of glaring police lights, passing headlights and having a flashlight pointed directly in the face.
Other issues which may compromise FST results include bad weather, poor roadside conditions such as gravel on the shoulder, nervousness caused by intimidating behavior from the police officer and the stress of being investigated for DWI, as well as the suspect's footwear.
If you have been charged with DWI after failing the FSTs and believe that the test results were prejudiced against you, it may be possible for you to avoid a conviction if you retain a skilled attorney to represent you in court.