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Field sobriety tests may not work for marijuana intoxication

| Jul 1, 2021 | Criminal Defense

Because operating a vehicle while impaired violates Indiana law, you may face charges for driving a car with a blood alcohol concentration above the legal limit. You may not realize, however, marijuana intoxication may also lead to OWI charges.

Officers must have reasonable suspicion to stop you for an OWI offense. Reasonable suspicion may include stumbling before entering your car, driving erratically or even having a burned-out taillight. To confirm intoxicated driving during a stop, officers may ask you to perform a field sobriety test.

Field sobriety tests

Officers use the following three field sobriety tests to evaluate whether a person may be under the influence of alcohol or drugs:

  • Horizontal gaze nystagmus
  • Walk and turn
  • One-leg stand

When drivers perform poorly on one or more of these tests, officers often request a breath, blood or urine sample for testing. These tests are good at determining whether a person’s BAC exceeds the legal limit in Indiana, which is 0.08%

Marijuana impairment

While using marijuana may impair an individual’s ability to drive, field sobriety tests and chemical tests may not reliably measure marijuana impairment. In fact, a recent National Institute of Justice study found no correlation between performance on field sobriety tests and THC levels in biofluids.

Because driving while under the influence of marijuana may lead to serious charges, it may be necessary for you to explore all options for defending yourself. Ultimately, depending on both your performance during field sobriety testing and the levels of THC in your system, you may be able to use the NIJ study to your advantage.