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Flawed Drug Lab Tests Lead to False Confessions

By Christopher Coble, Esq. on February 19, 2016 | Last updated on March 21, 2019

A confession can be a powerful piece of evidence against a criminal defendant, often negating the need for a trial entirely. And in the vast majority of criminal cases, a defendant will admit guilt to charges as part of a plea bargain. This is all well and good, assuming those confessions are true. But that's not always the case.

Defendants give false confessions for a variety of reasons, mostly in the face of overwhelming evidence of their guilt. But what happens when that evidence is faulty? Harris County, Texas is finding out: the jurisdiction just released a report on dozens of exonerations after drug possession guilty pleas were based on inaccurate drug tests. So how is this happening?

Faulty Field Tests

Last year, Harris County overturned 43 criminal convictions, 42 of which were for drug possession. In each of those 42 cases lab tests later revealed that whatever people were possessing, it wasn't drugs. (The Washington Post's Radley Balko points out that notoriously error-prone field tests will return false positives for "chocolate cookies, motor oil, spearmint, soap, tortilla dough, deodorant, billiards chalk, patchouli, flour, eucalyptus, breath mints, Jolly Ranchers and, infamously, loose-leaf tea.")

False positives from field drug tests led to 41 false confessions to drug possession over the last two years in Harris County. Possessing even trace amounts of drugs in Texas is a felony, and it appears that many defendants were pleading guilty to avoid lengthy prison sentences. Most of the people who had no prior record and pled guilty served no time in jail.

Broken Crime Lab

This is a good first step for Harris County, but it is by no means the end of the road. Problems with their crime lab results stretch back decades, with the most recent scandal in 2013 when an investigation found that a lab tech was fabricating the results of thousands of drug tests. And this latest report noted "200 additional guilty plea drug conviction cases with lab reports indicating no illegal drugs are still being processed."

It may sound odd, but just because a person confessed doesn't mean they are guilty. Especially when that confession is based on invalid evidence. Before confessing to any crime, you should consult with an experienced criminal defense attorney first.

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