In December, Texas local Ross LeBeau was pulled over for a traffic violation when he made a right-hand turn without stopping. When LeBeau admitted to Harris County police that he had a small amount of marijuana, the police preceded to search the car, and came across a much larger find: 252 grams of meth.

Except … LeBeau didn’t have any meth at all. Further testing of the substance at the Institute of Forensic Science revealed that what was actually in the car was kitty litter.

This was good news for LeBeau and bad news for the Harris County police, which at the time of arrest said it was “another example how a routine traffic stop turned into a significant narcotics arrest in our community and may have kept our children and loved ones free from being introduced to drugs.”

How could the police get it so wrong? The answer comes down to bad field tests and bad policing. Kitty litter, while sometimes consisting of “crystals”, is not crystal meth.

When the police pulled over LeBeau, they used their “powers of observation” and two field drug tests to determine that the kitty litter was meth. These field tests led to two false positives, categorizing what cats pee in as the addictive central nervous system stimulant.

Meth is chemically composed of carbon, nitrogen, and hydrogen; common ingredients to make meth include acetone, lithium, toluene, hydrochloric acid, pseudoephedrine, red phosphorus, sodium hydroxide, sulfuric acid, and anhydrous ammonia.

Not the same.

Comparatively, kitty litter is typically either made from a highly absorbent clay called sodium bentonite or silica crystals, that are typically a blend of sand and sodium bentonite. Since the Harris police described the “meth” as “small clear, blue and gold covered nuggets” it’s likely that the litter was something like Fresh Step which includes silica gel derived from sodium bentonite, limestone, activated charcoal, borates (an antimicrobial agent), and Febreze, which the active ingredient hydroxypropyl beta-cyclodextrin.

The chemical compositions of meth and kitty litter are different — but the field tests couldn’t tell. And while it may seem comical at first, this result is actually indicative of a huge issue in American drug policing. According to investigative reporting from ProPublica, no central agency regulates the manufacturing and sale of the test and there are no comprehensive records kept on their use. The kits have changed little since their 1973 debut and cost about $2. Even their creator, chemist L. J. Scott, Jr. — who typically defends them — told ProPublica that “no field test is fail safe” and “any field test can give you an erroneous result, even if you run two or three field tests in a row.”

And the inaccuracies of these tests have real results. For example, Florida’s Department of Law Enforcement found that 21 percent of evidence listed by police as meth was not, in fact, meth. In a 2014 report the Las Vegas police department reported that field tests are vulnerable to error — but to this day continue to use them as evidence for three-quarters of their drug convictions.

LeBeau could have spent at least two years in jail — all because he tried to use kitty litter in a sock to keep his car windows from fogging up.

Photos via Wikimedia Commons/Flickr, Giphy