Hundreds of law enforcement agencies in Michigan and around the country use chemical field test kits to identify illegal drugs during traffic stops. The kits are also used by corrections departments to check inmate mail for controlled substances. They are popular because they only cost about $2 and are very easy to use. They are also unreliable. In 2018, a judge in California ruled that portable drug testing kits do not meet the admissibility standard for scientific evidence. In 2021, a Massachusetts judge described the kits as “arbitrary and unlawful guesswork.”
Drug convictions overturned
A database updated by the National Registry of Exonerations reveals that more than 130 drug convictions have been overturned because drug test kits identified benign substances as illegal drugs. The drug test kits are made up of plastic pouches that contain chemicals. When a substance like heroin, methamphetamine or cocaine is placed in the plastic pouches, the chemicals change color. The problem is that dozens of common and completely legal substances trigger the same reaction.
Hot weather and acne medication
Cobalt thiocyanate is one of the chemicals used in the kits. The chemical turns blue when it is exposed to cocaine, and it also turns blue when it comes into contact with approximately 80 other compounds including acne medication and several common household cleaners. The kits often do not work correctly even when illegal drugs are present. The chemicals change color very slowly in cold weather, and they sometimes do not change color at all in hot environments. When their clients are arrested based on the results of a roadside drug test, experienced criminal defense attorneys may delay plea negotiations until more reliable tests have been conducted.
Cheap and ineffective
These drug test kits would no longer be used if they cost hundreds of dollars each. Police and corrections departments around the country continue to use them despite all of their shortcomings because they are cheap. However, money may be the thing that puts an end to drug test kits. That is because inmates who were treated unfairly because benign substances were identified as illegal drugs and motorists who were arrested after household cleaners triggered a chemical reaction are now filing lawsuits and demanding compensation.