About 1.5 million people are arrested on drug charges every year, and approximately 773,000 of them are taken into custody after a drug field test identified a substance in their possession as a controlled substance. Field drug testing kits are used by Maryland law enforcement agencies because they are easy to use and inexpensive. They are also highly unreliable. According to a report released by the University of Pennsylvania in January 2024, about 30,000 people are wrongfully arrested each year because field drug tests identify benign substances as illegal drugs.
Drug field tests
The field drug tests used by police contain plastic bags filled with chemicals. When a controlled substance is placed in the bags, the chemicals change color. They are considered unreliable because dozens of benign and quite legal substances trigger the same chemical reaction. Researchers from the University of Pennsylvania’s Quattrone Center for the Fair Administration of Justice found cases where people were arrested because field tests identified donut glaze, cotton candy, sand and bird droppings as controlled substances.
No better than a coin flip
The controversy surrounding field drug test kits has prompted law enforcement agencies in some parts of the country to stop using them. In September 2023, the Jacksonville Sheriff’s Office stopped using the kits after discovering that they identified several over-the-counter cold remedies as cocaine. In 2021, a judge in Massachusetts ordered prison authorities to stop using the kits after determining that they were of little more value than a coin flip. When people are charged with drug offenses because of the results of field drug tests, they often plead guilty even when the substances tested are legal. Between 2004 and 2015, 212 people pleaded guilty to drug possession in Houston based on field drug tests that were later invalidated.
Inexpensive and unreliable
Field drug tests are used by police officers around the country because they are simple and inexpensive. They are also unreliable because the chemicals they contain react to dozens of benign substances as well as illegal drugs.
