On July 20, it was reported that a roadside test used in a Texas county provided false positives that led to nearly 300 convictions on drug-related charges over a period of approximately 10 years. Many of the defendants reportedly pleaded guilty so that they would be released from custody faster.
The test that was used in these cases uses a chemical called cobalt thiocyanate. When it is exposed to cocaine, it turns blue. However, the chemicals also turn blue when they are exposed to other compounds, which may include certain acne medications and even household cleaners. The creator of the test defended it by arguing that those who were not dealing drugs or using drugs would plead not guilty. This particular test is also used in other states.