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In every state in the union it is unlawful to operate a motor vehicle while under the influence of marijuana. In driving under the influence of marijuana cases, the prosecution must prove beyond a reasonable doubt that the driver was so impaired at the time of driving, that the driver could not operate a motor vehicle safely. Unlike alcohol, there is no accurate way to measure THC levels (the active ingredient in marijuana) since it is difficult to know when the actual intake of marijuana actually occurred and because a person can test positive for marijuana for up to thirty days after first using marijuana. Measuring alcohol is a different story. Most jurors understand that a blood alcohol level of over 1.0 usually means the driver was “per se” too impaired to drive a motor vehicle safely. Marijuana is a different story.
Without a viable and reliable way to measure the level of THC in a driver, the police must resort to using other forms of testing such as conducting field sobriety tests on the driver. These tests are by nature very subjective and problematic to administer fairly. Field sobriety tests are used by the officer to determine if, in his or her professional police opinion, the driver was so impaired he or she could not operate a motor vehicle safely and therefore should be arrested for driving under the influence of marijuana.
The driver is usually ordered out of the vehicle to perform field sobriety tests. While standing on the side of the road, an officer puts the driver through a series of balance, coordination, and mental acuity tests. While each jurisdiction uses its own field sobriety tests, there are some common tests used by practically all police agencies.
Balance tests
The driver is usually asked to stand on one foot and lean back with their eyes closed. Another balance favorite is asking the driver to walk an “imaginary line” usually in darkness of night. Innocent factors effecting balance tests include the actual location and conditions surrounding the test (on the roadside with cars speeding by), the lighting (dark, poorly lighted), the actual surface and pitch of the test area (loose gravel or dirt, uneven or slanted), the weather (cold, rainy, windy, snowy), and the drivers shoes (boots, heels, stiff dress shoes) all play a role in determining the accuracy of the testing. Interestingly, the loss of balance is not usually associated with being under the influence of marijuana. Notwithstanding, law enforcement continues to use these forms of tests to determine sobriety and safe driving.
Coordination tests
The driver, using one hand, is usually asked to touch each finger with the thumb, going from the index finger to the pinky finger and then back down again. This apparently demonstrates dexterity and the ability to follow instructions. Other popular coordination tests include asking the driver to count backwards while touching the nose with the tip of the index finger and while the drivers eyes are shut closed. Not only are these tests difficult to do when completely sober, the test is affected by the actual test conditions and the officers own ability to give clear and concise directions. All too often the officer does a poor job of explaining exactly what is required.
Mental tests
Reciting the alphabet, counting backwards from a random number ("count backwards from 73 to 57" or "count backwards from 100 by 7s") is all part of testing a driver’s mental acuity and capacity to focus on a task. Most experienced criminal defense attorneys can point out that these tests are often misleading since they are usually administered late at night, while the subject is nervous, tired and under interrogation. Further, the officer's opinion of poor performance on these field sobriety tests does not necessarily indicate the driver was so impaired he could not operate a vehicle safely.
Unlike the drunk driver, the driver under the influence of marijuana does not typically display the same types of deficits in balance, coordination and mental acuity that are so often produced by alcohol intoxication.
Just because driving under the influence of marijuana is more difficult to prove with any degree of certainty, one should not underestimate the penalties if one actually gets convicted of the offence. The penalties are serious and a conviction for driving under the influence of marijuana can result in fines, jail time and loss of driving privileges. For more information riving under the influence of marijuana and state penalties and laws visit GotTrouble.com