Maryland residents may be interested to learn about a relatively novel drug testing tool that has been leading to wrongful convictions in multiple states. This year, Nevada reported that it had overturned the convictions of five individuals who had been arrested and pleaded guilty to drug charges after substances in their possession tested positive for cocaine. The substances were tested by police using roadside drug tests. Only later did laboratory tests reveal that the substances were not, in fact, illicit.
Roadside drug tests result in false positives
The convictions in Nevada, which were overturned in 2017, were not the first wrongful convictions resulting from roadside drug tests: Oregon also overturned five drug convictions, and Houston, Texas, overturned over 250 convictions. All of these convictions resulted from roadside drug tests that had produced false positives for illegal substances.
How the roadside drug tests work
Roadside drug tests are a cheap and fast means for police officers to test a substance at the time a suspect is detained. Officers use the test by taking a sample of the drug and putting it into a liquid, which is supposed to change to a particular color if the substance is an illicit one like cocaine or methamphetamine. Studies have demonstrated that these tests are sufficient to establish probable cause to make an arrest but that they are not reliable enough to support a conviction.
Challenging the roadside drug test results
Even though the roadside test are unreliable, many prosecutors rely on the results of these roadside drug tests in pressuring defendants to plead guilty to drug charges. Prosecutors may do this even though many judges have barred prosecutors from presenting evidence of the roadside drug test results at trial due to their unreliability.
Unfortunately, when someone pleads guilty, police officers will often destroy evidence of the tests, meaning they cannot be retested by a laboratory. Individuals accused of a drug crime may want to retain a criminal defense attorney early on to help challenge the results of any tests and ensure that all evidence is preserved.