Most law enforcement agencies in Texas and around the country issue their officers, troopers or deputies with portable kits that are used to determine whether or not suspicious substances are illegal drugs. These kits are popular because they are inexpensive and very easy for officers to use, but several studies have revealed that they are also extremely unreliable. Officers drop suspicious substances into plastic bags filled with chemicals and, then, look to see if the chemicals have changed color. While drugs like cocaine and methamphetamine will cause the color of the chemicals to change, so will benign substances like sugar or baking soda.
Due to these issues, courts have consistently refused to allow evidence obtained by field testing to be introduced in narcotics cases, but the vast majority of individuals taken into custody on drug charges choose to avoid a trial by pleading guilty. In these situations, the alleged illegal drugs are rarely sent to laboratories for more rigorous testing. Despite these problems, the use of drug-testing kits has actually grown in recent years.
Problems with drug-testing kits have prompted prosecutors in Oregon and Texas to overturn more than 200 drug convictions. Prosecutors in Nevada reported recently that five narcotics cases were overturned in 2017 because of questionable field-test results. Substances initially identified as cocaine were later found to be benign. The five defendants, who all pleaded guilty to drug possession, were arrested between 2011 and 2013. One of them spent eight months behind bars.
Criminal defense attorneys with experience in narcotics cases are likely aware of the shortcomings of drug-testing kits, and they may urge their clients not to accept plea offers when police officers have only gathered this type of evidence. These issues also highlight how important it can be for criminal suspects to avail themselves of qualified legal advice before answering questions or making important decisions when facing drug charges.