Drug Tests in the Field are Unreliable — Here’s Why

drug tests, Drug Tests in the Field are Unreliable — Here’s Why

Imagine this: You’re driving home after indulging in some powdered donuts after a long day. You forget to signal and change lanes, then see flashing lights behind you. “All this for a missed signal?” you think. But of course, you pull over.

When the officer walks over to your lowered window, he takes a look at you and then asks you to step out of the car.

“Why?” you ask. You figured you’d hand over your license and registration and be on your way with a new citation and fine.

After being directed out of the vehicle again, you brush off the white powder that has clung to your shirt. You’re scared, but you know to do what you’re told (within reason).

Unfortunately, now the officers want to search your car. They feel they have probable cause—you were driving erratically, and there’s a powdery white substance you’re trying to hide. Depending on the officers, they may ask you whether they can search your vehicle (which you should always say no to unless they have a warrant), or they may just decide they have enough evidence to search your vehicle without your consent. Or they may choose to administer a field drug test. Thinking you have nothing to worry about with a drug test, you take it so you can get this all over with.

Then comes a big shock—they’ve found traces of cocaine in the substance that was covering your hands. Knowing you’ve never touched the stuff, you think you can explain it all away. It was just a donut, right?

Field Reagent Tests: Unreliable and Still Prevalent

If you’ve been given a drug test after a traffic stop, it was likely a field reagent test. These tests are popular because they’re fast, small, and cheap. Unfortunately, even one manufacturer of these tests has stated that “Users of our kits run into stuff that mimics or duplicate positive reactions all the time” (Sirchie). Another manufacturer, SafariLand Group, says that they shouldn’t be used to establish probable cause on their own.


Because they’re surprisingly unreliable. Tests have been done to check the accuracy of these field tests and simple, everyday substances, including chocolate, coffee, and even air came up as testing positive for drugs even though they did not include any illegal substances. In addition, over the counter medications also had positive test results. As far as we know, however, there is no law against operating a motor vehicle under a legal dose of ibuprofen.

The current field test utilizes a capsule full of a reactive chemical. This capsule is in a baggy. To do the test, an officer places the suspect substance in the baggie and breaks the capsule, releasing the reactive chemical. The chemicals will turn a particular color depending on the substance in the bag. An officer must then use his or her judgment to determine what color the bag has turned. This can lead to confusion and misjudgment based on the time of day, how long the capsule takes to work, and even an officer’s ability to see color properly.

Once the test comes back positive for a suspected illegal substance, officers take this as a probable cause (officers need either probable cause or a warrant to do a search). They then believe they can search your vehicle and person and place you under arrest. While it is likely that additional testing will clear an individual who is only covered in powdered sugar, the amount of time and money lost by then can be harmful to an accused’s future.

Research is underway to develop a better field drug test that is more reliable, but there’s no telling as to when that test may be available. And whether police departments will make the jump to what is likely to be a more expensive solution.

Now, you may think that the widespread knowledge that these field tests are unreliable would lead to police departments using alternative methods to determine probable cause. Unfortunately, you’d be wrong.

Since a 2016 ProPublica and New York Times report shared the widespread false positives, most departments have continued to rely on these completely unreliable tests, sending innocent people to jail for days and even months until they can gather money to pay bail or be confirmed innocent by a state crime lab. Often, it is individuals who are unable to make bail who pay the largest cost.

This is unacceptable.

There is no reason an individual should be jailed on evidence that has repeatedly been shown to be faulty. Law enforcement must do better.

From the Headlines

In 2018, the Miami Herald published a story about Rebecca Shaw, a Tampa Bay mom who was jailed for five months in 2015 because a field drug test showed a false positive on her vitamins. She was charged with trafficking in oxycodone. Had her husband not been able to finally bail her out after 5 months, she would’ve stayed in jail for an additional 7 months while the state lab finished testing her supplements (the test did come back as vitamins). All this because she ran out of gas and consented to an unwarranted search of her vehicle.

Daniel Rushing of Orlando had a similar experience the same year when he was arrested for being in possession of “meth.” It was the glaze off of a Krispy Kreme donut.

In 2017, Karlos Cashe of Oviedo was arrested for possession of “cocaine”—which was actually drywall dust. He spent 90 days in jail.

These stories are becoming more common. Too often, individuals lose their jobs, face financial difficulties, and have their custody challenged because of false drug test results! If you’re facing false charges, you must speak to a lawyer now!

Bad Drug Test? Call Mike G!

If you believe you or a loved one has been the victim of a false positive and are now stuck in legal limbo or facing drug charges, it’s crucial that you speak with a skilled Tampa defense attorney. It is too easy for the legal system to trample the rights of the voiceless—make sure you have a powerful voice on your side. Call Mike G Law today.

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