San Diego Criminal Lawyers Blog
Absent the distinctive scent associated with smoking marijuana, how can the police determine if you are driving your vehicle under the influence of marijuana? Marijuana use for personal consumption is legal in California. It is illegal, however, to drive under the influence of marijuana in California.
Field Sobriety Testing
When the police stop a driver under suspicion of driving under the influence of alcohol or drugs, including marijuana, but cannot readily observe marijuana use, they may request that the driver participate in field sobriety tests to determine if he or she is impaired by alcohol or drugs.
Generally, a suspected impaired driver may be asked to perform a series of the following tests:
- The one-legged test requires you to stand on one leg for a period of time. If you are able to do so, you pass this test.
- The walk and turn test requires you to walk in a straight line. You are evaluated for balance, staying on the line, walking and stopping, and following directions. If you are able to remain on the line walking as instructed, you pass this test.
- The horizontal gaze nystagmus test, also known as the HGN test, requires you to follow the gaze of the police officer’s finger or an object in the police’s hand. You are evaluated for compliance with the instructions and the nature of your eye movements. If you are able to follow the gaze as instructed, you pass the test.
If you fail the field sobriety tests, the police have probable cause to arrest you under suspicion of driving under the influence of marijuana.
Chemical Tests
Every time you drive on California’s roadways, you have already consented to submit to a chemical test if asked to participate in one by law enforcement. Once in police custody, law enforcement may require you provide samples of your blood, breath, or urine to conduct chemical tests. With respect to marijuana use, the tests would measure the presence of THC, the active ingredient in marijuana to support the DUI (marijuana) element of the charge. As of the Spring of 2019, there is no breath technology that can measure THC in a person’s breath in use by San Diego’s Police Department. All three tests are less able to measure THC as time passes.
Cotton Swab Tests
In San Diego, police at DUI checkpoints may use a cotton swab to collect a saliva sample from a driver. The cotton swab test can detect the presence of THC as well as crystal meth, methadone, cocaine, and some prescription drugs.
Charged with illegal use or possession of marijuana or driving under the influence of marijuana in San Diego? Hire a knowledgeable and experienced San Diego criminal defense lawyer to help you resolve your case. Continue reading