The True Cost of This $2 Drug Test

July 16th 2016

A cheap roadside drug test used by police officers around the U.S. — one that contributes to tens of thousands of drug possession convictions each year — frequently produces false positives, an investigation by ProPublica's Ryan Gabrielson and Topher Sanders found.

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The $2 field tests are meant to help officers identify illicit substances, but they haven't evolved much since they were patented in 1973. And the Justice Department said they "should not be used for evidential purposes," rendering them inadmissible in court.

Yet there are nearly 100,000 drug convictions each year based on these field tests, mainly through plea bargains before a trial even takes place, ProPublica reported.

Here's how it plays out: A cop pulls you over and sees something that resembles an illegal drug. He whips out the field test, which contains a set of chemicals that are supposed to change colors when certain drugs are detected. The police file charges based on what the tests show, and use those results as leverage to obtain a plea bargain.

The problem is, the tests are fallible.

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One common field test changes colors when illegal drugs are introduced, but it turns the same color for more than 80 other legal substances, including acne medication. Temperature can affect the test results, poor lighting can make it difficult to identify colors, and poor training has led officers to misinterpret results.

Gabrielson and Sanders reported:

"There are no established error rates for the field tests, in part because their accuracy varies so widely depending on who is using them and how. In Las Vegas, authorities re-examined a sampling of cocaine field tests conducted between 2010 and 2013 and found that 33 percent of them were false positives. Data from the Florida Department of Law Enforcement lab system show that 21 percent of evidence that the police listed as methamphetamine after identifying it was not methamphetamine, and half of those false positives were not any kind of illegal drug at all. In one notable Florida episode, Hillsborough County sheriff’s deputies produced 15 false positives for methamphetamine in the first seven months of 2014."

Even if you assume that the error rate is relatively small — say, 10 percent — you're still talking about thousands of false positives that possibly led to wrongful drug possession convictions. That's because most "drug cases in the United States are decided well before they reach trial, by the far more informal process of plea bargaining," ProPublica reported.

Hillsborough State Attorney Mark Ober defended the use of field drug tests, telling Fox 13 that the tests "continuously proven to be a reliable resource for probable cause determination" when "used and interpreted correctly."

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Federal agencies recognize that these tests aren't great, which is why prosecutors are required to produce the results of a secondary lab test for reliable evidence in drug cases. The Justice Department also added a labeling requirement in 2000, stating that "users of the kit should receive appropriate training in its use and should be taught that the reagents can give false-positive as well as false-negative results." (The companies that manufacture these drug test have abided by this requirement — though at least one company, Sirchie, updated the label on its test following ProPublica's inquiry.)

The way most drug cases go in the criminal justice system renders these safeguards pretty much useless, Gabrielson and Sanders said. Nine out of 10 prosecutors nationwide "accepted guilty pleas based solely on the results of field tests," according to a 2011 report from the nonprofit research group RTI International.

"This puts field tests at the center of any discussion about the justice of plea bargains in general," ProPublica reported.

"The federal government does not keep a comprehensive database of prosecutions in county and state criminal courts, but the National Archive of Criminal Justice Data at the University of Michigan maintains an extensive sampling of court records from the 40 largest jurisdictions. Based on this data, we found that more than 10 percent of all county and state felony convictions are for drug charges, and at least 90 percent of those convictions come by way of plea deals."

[h/t ProPublica]

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