Tens of thousands have been convicted and served time—even earning the black mark of a felony—for crimes they likely didn’t commit, a recent report found, because the cases against them relied on horribly unreliable field drug test kits.

So prone to errors are the tests, courts won’t allow their submission as evidence. However, their continued use by law enforcement—coupled with a 90 percent rate at which drug cases are resolved through equally dubious plea deals—needlessly ruins thousands of lives.

In New York Times Magazine, ProPublica’s Ryan Gabrielson and Topher Sanders note that although a popular $2 field test kit for illegal drugs hasn’t been modified significantly since 1973, it remains the backbone for countless convictions and guilty pleas for tens of thousands of doubtlessly innocent people.

One variety of field test, the reporters explain:

“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 development; heat speeds it up, or sometimes prevents a 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.”

Error rates, in the context of the over 1.2 million people arrested in the U.S. each year for illegal drug possession, could easily be considered astronomical—even though department figures also vary widely.

Between 2010 and 2013, re-examination of tests by authorities in Las Vegas found a false positive rate of 33 percent, while lab system for the Florida Department of Law Enforcement’s own data “show that 21 percent of evidence that 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”—worse, some of those officers simply misunderstood which color indicated an ostensibly positive result.

Without stating as much, the report suggested systematic intimidation often traps people into situations they feel would be unwinnable—such police threatening to summon drug-sniffing canines to manufacture consent, or when prosecutors bluster with lengthy sentences to essentially force defendants into otherwise unacceptable plea arrangements—often when a putative suspect committed no crime at all.

Color test kits exploded in popularity around the country, Gabrielson and Sanders noted, almost immediately following then-Pres. Richard Nixon’s 1973 declaration of war on drugs—itself conceptualized under the guise of moralistic imperative because, the president’s chief advisor later admitted, “We knew we couldn’t make it illegal to be either against the war or black,” and the antiwar left and black people comprised the administration’s primary adversaries.

But those field test kits promptly came under fire, as National Bureau of Standards warned in 1974, they “should not be used as sole evidence for the identification of a narcotic or drug of abuse”—a determination echoed by the Department of Justice in 1978, saying the tests “should not be used for evidential purposes.” Secondary, specialized—and far more accurate—tests are required for prosecution in virtually every location in the U.S.

However, those caveats haven’t exactly been heeded.

A 2011 report from RTI International, cited by NYT Magazine, “found the prosecutors in nine of 10 jurisdictions it surveyed nationwide accepted guilty pleas based solely on the results of field tests,” and Gabrielson and Sanders “confirmed that prosecutors and 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.”

Plea bargains comprise a startling percentage of felony drug convictions: The reporters discovered roughly 90 percent of those nationwide had been handed down through plea deals, though strikingly higher rates were found in Tennessee, with 94 percent; Kansas, at over 97 percent; and Harris County, Texas, home to Houston, the rate of felony drug convictions from plea deals is a staggering 99.5 percent.

Taking field test error rates, and the subversion of rights and perversion of justice effected through plea-bargaining, the failed and falsely-premised war on drugs creates an astonishing number of criminals not guilty of any crime—drug-based or otherwise.

Worse still, and similarly observed by Jacob Sullum for Reason, all of the aforementioned ignores the absurdity of felony convictions based purely on quantities of putatively illegal substances so minuscule they defy the concept of criminality. One anecdotal example from NYT Magazine illustrated the case of a woman whose felony drug conviction—among other alarming details—was bargained for an amount equal to just two-hundredths of a gram.

Police violence is epidemic in the United States, and retaliation—as in the case of Dallas—has now become tangible reality. But an astounding number of policing’s ills can be directly linked to the sham war on drugs and its criminalization of not only substances, but being poor—or, perhaps more aptly, human in the wrong place at the wrong time.

When law enforcement isn’t tasked with protecting people from legitimate, violent criminals, but rather policing people from themselves through their choice of vice, society suffers the consequences. Violent crimes go largely unsolved, while innocent people are gunned down by nervous police whose primary job amounts to revenue-generation through the search and seizure of ‘illicit’ substances—drugs which, if legal, would ‘harm’ no one other than the user.

When advocates and activists, privacy-rights hawks and even some politicians, say “the system is rigged,” this farcical feeding of the prison-industrial complex and its arbitrary criminalization of non-violent ‘crime’ is an enormous part of that.

While no act of aggressive violence should be tolerated or condoned, ire at this broken system virtually guarantees the cycle of killing by police and retaliation by civilians will continue unabated—rather, unabated until the State tucks tail and admits the war on drugs has outlived its guise and, indisputably, needs to end.

During the short video below, the researchers demonstrate how easy it is for police to generate a false positive during a field test for drugs.

The group tests over the counter Tylenol PM in a police test kit for cocaine—the test kit says the Tylenol is cocaine.

The group also tests the most popular chocolate in the world, Hershey’s chocolate, for marijuana, it also tests positive.

Perhaps the most disturbing test was when the group put absolutely nothing into the field test kit, and they received a positive result.