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False positives on drug tests can lead to wrongful arrests, convictions

If you drink loose tea that contains oregano, peppermint, basil, St. John's Wort, eucalyptus or a host of other ingredients, you could be charged with possession of marijuana. If you eat sugar-coated pastries in the car and drop white crumbs on the floor and you are stopped, you could be arrested for possession of cocaine.

False positives

Why are these innocuous substances getting people in trouble? Because the chemicals used in field tests for drugs also give a false positive on these substances; and sometimes, just because it is human error. Cobalt thiocyanate, the chemical used to determine if a substance is cocaine, turns blue when it is exposed to over 80 compounds, including some acne medications, methadone and several cleaners you use in your home.

The NarcoPouch KN, used to test for marijuana, turned positive on 33 of 42 substances tested in a 2008 and 2009 study performed by Claflin University. Those substances included marijuana, peppermint, lemon grass, spearmint, chicory flower, cypress, St. John's work, bergamot, vanilla, basil and several other innocuous plant materials. The NIK Duquenois-Levine Reagent System did not have as many false positives, but still had several when tested on the same plant matter.

Tests are extremely flawed

According to a recent article, in Florida, a study found that 21 percent of the evidence collected and tested by police was labeled as methamphetamine when in fact, it was not - it was not even an illegal drug. The district attorney for Travis County, Texas stopped accepting guilty pleas based on the results of field testing in 2013 because her office found that there were at 12 false positives in one six-month period.

The Marshall Project's Alysia Santo stated that a lieutenant with the sheriff's office in Hillsborough County, Florida reported that he opened a NARK II field test to the air and the chemical turned purple, just like it would when exposed to methamphetamine.

Contact our office

These instances of rampant false positives is a reminder that if you or a loved one have been accused of drug possession based on the results of a drug test, it is important to take immediate action to aggressively fight the charges. Experienced criminal attorney Edward R. La Rue can examine the evidence against you and formulate an effective legal strategy to ensure the best possible outcome, including a dismissal of the charges against you.

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