* Pro Publica estimates that at least 100,000 people every year plead guilty to drug-possession charges which rely on inexpensive (often two dollars each) police field-test results as evidence…

Police officers arrest more than 1.2 million people a year in the United States on charges of illegal drug possession. Field tests like the one Officer Helms used in front of Amy Albritton help them move quickly from suspicion to conviction. But the kits — which cost about $2 each and have changed little since 1973 — are far from reliable.

The field tests seem simple, but a lot can go wrong. Some tests, including the one the Houston police officers used to analyze the crumb on the floor of Albritton’s car, use a single tube of a chemical called cobalt thiocyanate, which turns blue when it is exposed to cocaine. But cobalt thiocyanate also turns blue when it is exposed to more than 80 other compounds, including methadone, certain acne medications and several common household cleaners. Other tests use three tubes, which the officer can break in a specific order to rule out everything but the drug in question — but if the officer breaks the tubes in the wrong order, that, too, can invalidate the results. The environment can also present problems. Cold weather slows the color development; heat speeds it up, or sometimes prevents a color reaction from taking place at all. Poor lighting on the street — flashing police lights, sun glare, street lamps — often prevents officers from making the fine distinctions that could make the difference between an arrest and a release.

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. When we examined the department’s records, they showed that officers, faced with somewhat ambiguous directions on the pouches, had simply misunderstood which colors indicated a positive result.

No central agency regulates the manufacture or sale of the tests, and no comprehensive records are kept about their use. In the late 1960s, crime labs outfitted investigators with mobile chemistry sets, including small plastic test tubes and bottles of chemical reagents that reacted with certain drugs by changing colors, more or less on the same principle as a home pregnancy test. But the reagents contained strong acids that leaked and burned the investigators. In 1973, the same year that Richard Nixon formally established the Drug Enforcement Administration, declaring “an all-out global war on the drug menace,” a pair of California inventors patented a “disposable comparison detector kit.” It was far simpler, just a glass vial or vials inside a plastic pouch. Open the pouch, add the compound to be tested, seal the pouch, break open the vials and watch the colors change. The field tests, convenient and imbued with an aura of scientific infallibility, were ordered by police departments across the country. In a 1974 study, however, the National Bureau of Standards warned that the kits “should not be used as sole evidence for the identification of a narcotic or drug of abuse.” Police officers were not chemists, and chemists themselves had long ago stopped relying on color tests, preferring more reliable mass spectrographs. By 1978, the Department of Justice had determined that field tests “should not be used for evidential purposes,” and the field tests in use today remain inadmissible at trial in nearly every jurisdiction; instead, prosecutors must present a secondary lab test using more reliable methods.

But this has proved to be a meaningless prohibition. Most drug cases in the United States are decided well before they reach trial, by the far more informal process of plea bargaining. In 2011, RTI International, a nonprofit research group based in North Carolina, found that prosecutors in nine of 10 jurisdictions it surveyed nationwide accepted guilty pleas based solely on the results of field tests, and in our own reporting, we confirmed that prosecutors or judges accept plea deals on that same basis in Atlanta, Boston, Dallas, Jacksonville, Las Vegas, Los Angeles, Newark, Philadelphia, Phoenix, Salt Lake City, San Diego, Seattle and Tampa.

* I asked the Illinois State Police for comment…

Hi Rich,

The ISP utilizes field test kits (similar to the illustration in the attached link you sent) to aid in establishing probable cause for arrest by detecting the possible presence of narcotics. Field test kit results are considered presumptive. The ISP laboratory utilizes scientifically validated methods for confirmatory testing of specimens to determine the presence of narcotics in submitted evidence.

* I asked what “presumptive” meant, exactly. The spokesman pointed me to this passage in a policies and procedures manual…

Involvement in the criminal justice system begins with an alleged violation of state criminal law or local or municipal ordinance. Individuals can enter police custody in different ways. A police officer may directly observe a violation of the law or ordinance or may be called to investigate a report of a possible crime. In either case, when a police officer determines that he or she has probable cause to believe an individual committed a criminal act, he or she can take that person into custody. Even with probable cause, a police officer may choose to release the individual and continue an investigation into the alleged offense. A police officer has discretion, limited by the police department’s policy, regarding what action he or she takes.

So I then asked how often the lab checks those field tests, and what the rate of false positives is on those follow-uptests. I was asked to submit a FOIA. I will and will let you know what I learn.

*** UPDATE ***  Sen. Don Harmon is also concerned about this issue and says he has already started looking into it. He texted me that there’s another problem with the tests: “The number of people held in Cook County Jail for almost a month and then released because of no probable cause is staggering. As is the associated cost of the taxpayer”…

We recently passed a bill to do a pilot program in Cook County, because all the other counties in the state are already using the field tests. Mike Z was the House sponsor.

The reason this is important is that people in Cook County are spending 20 to 30 days in jail, waiting for the results of the lab tests before even getting their probable cause hearing.

I’m concerned about the story regarding accuracy of the tests, and I’m already looking into it. But, at least in Cook County, I’m not sure that a false positive is worse than spending 20, 25, 30 days in jail only to have your case dismissed for no probable cause once you finally get your hearing. […]

In Cook, they won’t do the probable cause hearing without the lab results. Hence, the long wait in jail.

It’s also my understanding that judges are routinely throwing out small-amount cases, citing lack of probable cause, even when the field test or the lab test come back positive. apparently, it’s just not worth the time and effort to proceed. It’s like they’re viewing the 20 to 30 day stay in jail as the sentence already served.