No, I'm Not Using Slang. It Really Is Tea.

According to a new report (PDF) sponsored by the Marijuana Policy Project, field tests commonly used by police to identify marijuana and other drugs yield false positives in response to a variety of legal substances, resulting in the arrest and detention of innocent people. Worse, "millions of people have been, and continue to be, prosecuted and convicted of marijuana charges without proof that they possessed marijuana." The author, forensic drug expert John Kelly, says an investigation he conducted in collaboration with former FBI scientist Frederic Whitehurst "reveals a drug testing regime of fraudulent forensics used by police, prosecutors, and judges which abrogates every American's Constitutional rights."

Some of the cases Kelly cites may ring a bell. In April 2007, for instance, the NarcoPouch 928 drug test kit falsely fingered Don Bolles, drummer for the punk band The Germs, for GHB possession, reacting to a sample of Dr. Bronner's Magic Soap. "Subsequent testing," Kelly notes, "found that a wide variety of natural soaps as well as soy milk test positive for GHB." In August 2008, Ron Obadia and Nadine Artemis were detained at Toronto International Airport en route to the U.S. because the Duquenois-Levine color chemical test indicated that the raw chocolate they carried contained hashish. "Subsequent lab testing proved there was no hashish in the chocolate," Kelly writes. "They were released but stuck with a $20,000 legal bill." The same thing happened again the following month.

According to Kelly, "millions of people have been arrested, prosecuted, and convicted of marijuana charges on the basis of the Duquenois-Levine (D-L) color chemical test, both with and without a microscopic exam." Experiments with the D-L test described at the end of the report found that "patchouli, spearmint, and eucalyptus tested positive for marijuana, while lavender, cypress, and oregano (which previous studies showed produced false positives with the D-L test) gave inconclusive results." In tests using just the NarcoPouch KN Reagent kit, 33 of 42 substances—including vanilla, anise, chicory, and peppermint—tested positive for cannabis.

Nick Gillespie noted the Bolles case in 2007.