How do police test for driving high?

How Do Police Test for Driving High?

Driving under the influence (DUI) of drugs, particularly marijuana, has become a growing concern for law enforcement agencies worldwide. With the increasing legalization of cannabis and its widespread use, police have had to adapt their techniques to detect and prosecute individuals driving impaired. So, how do police test for driving high?

Visual Observation

The first step in determining whether a driver is impaired is through visual observation. Police officers are trained to look for signs of intoxication, such as:

• Glassy or bloodshot eyes: A driver’s eyes may appear red or bloodshot due to dilated blood vessels.
• Unusual behavior: A driver may exhibit unusual behavior, such as slurred speech, stumbling, or a lack of coordination.
• Slow reaction time: A driver may take longer than usual to respond to the officer’s instructions or exhibit a delayed reaction to unexpected events.

While visual observation is not a foolproof method, it can raise suspicions and prompt further testing.

Field Sobriety Tests (FSTs)

FSTs are standardized tests designed to assess a driver’s balance, coordination, and overall impairment. There are several types of FSTs, including:

• Horizontal Gaze Nystagmus (HGN): This test examines the driver’s eye movements while following a moving object with their eyes.
• Walk and Turn (WAT): The driver is instructed to walk a straight line, heel to toe, while performing specific tasks.
• One-Leg Stand (OLS): The driver is required to stand on one leg while raising the other.

These tests are designed to detect signs of impairment, such as:

• Nystagmus: Abnormal eye movements may indicate a level of intoxication.
• Lack of coordination: The driver may have difficulty completing the tasks or exhibit delayed reactions.
• Bail or swaying: The driver may exhibit an unsteady gait or lose their balance.

The results of these tests, combined with visual observation and other factors, can be used to determine whether the driver is impaired.

Standardized Field Sobriety Tests (SFSTs)

SFSTs are a set of FSTs that have been standardized and validated for their effectiveness in detecting impairment due to alcohol or drugs. The three primary SFSTs are:

• Vertical Gaze Nystagmus (VGN)
• Eye Movement Test (EMT)
• WAT

These tests are designed to detect signs of impairment, such as nystagmus, and are used in conjunction with other tests and observations.

Breath and Blood Testing

Once a driver has been arrested and brought to a police station, they may be required to undergo breath and blood testing. These tests are used to measure the levels of THC (tetrahydrocannabinol, the primary psychoactive compound in cannabis) in their system.

• Breath Testing: A breath sample is taken using a Datamaster DMT, which measures the levels of THC in the driver’s breath.
• Blood Testing: A blood sample is taken and sent to a laboratory for analysis. The results of the test can determine whether the driver’s THC levels exceed the legal limit.

Key Points:

• There is no universally accepted limit for THC in the bloodstream, as the effects of cannabis can vary greatly between individuals.
• Some jurisdictions have set limits, such as 5 ng/mL (nanograms per milliliter) in Oregon and 10 ng/mL in Colorado.
• Drivers who test above the legal limit may face criminal charges and penalties.

Other Tests and Investigations

Police may also use other tests and investigations to determine whether a driver is impaired. These may include:

• Drug Recognition Expert (DRE) evaluation: A DRE is a trained officer who uses a standardized protocol to evaluate a driver’s impairment.
• Preliminary Information Report (PIR): A PIR is a standardized form used to document the results of roadside testing and other observations.

Conclusion:

DUI laws have evolved to keep pace with changing social norms and increased awareness of drug-related impairment. Police use a combination of visual observation, FSTs, and standardized tests to determine whether a driver is impaired due to drugs, including marijuana. While the legal limit for THC is not universally accepted, law enforcement agencies continue to adapt their tactics to address the growing concerns surrounding drug-impaired driving.