Reports on Sandra Bland's Posthumous THC Levels Riddled With Bad Science

By Ellie Shechet | July 29, 2015 | 2:00pm

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There is something very off about a recent story circulated by the Associated Press on Sandra Bland’s toxicology report, which was released on Monday. It was mostly republished by right-of-center publications like the New York Post and Fox News, with little interest from the mainstream media—presumably because the article makes some questionable claims about Bland’s marijuana use, a handy conservative talking point that is depressingly familiar.

In the story, two expert toxicologists reviewed the report. The report stated that the level of THC (an active component of marijuana) in Bland’s system was at 18 micrograms per liter, which the Associated Press notes is “more than three times the legal limit for drivers in Colorado and Washington, states that permit the recreational use of marijuana.”

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University of Florida toxicology professor Bruce Goldberger was quoted as saying, ““I don’t think it’s possible to rule out the possibility of use while in jail,” a notion so unlikely that it seems odd to publicize it; no evidence has been found to back up that claim. Robert Johnson, chief toxicologist at the Tarrant County medical examiner’s office in Fort Worth, Texas, told the AP: “I have never seen a report in the literature or from any other source of residual THC that high three days after someone stops using the drug.”

What the Associated Press and its on-call experts failed (rather egregiously) to note is that THC levels redistribute and, more importantly, quite often rise after death. There is very little literature on residual THC in dead bodies, and the literature that does exist shows that postmortem THC levels are almost impossible to pinpoint exactly. Even with living people, there is no definitive scientific consensus on what THC level constitutes impairment; the decision to set a legal driving limit based on this measurement was extremely controversial. Its presence in a toxicology report is not enough to presume impairment at the moment of death with any kind of certainty, which Dr. Goldberger—who also helped George Zimmerman’s lawyers make the claim that Trayvon Martin had enough marijuana in his system for impairment—did.

Speaking about the THC levels of a deceased person in the same terms as THC levels in a living person was an irresponsible and misleading choice. The New York Times investigated this discrepancy, quoting leading forensic toxicologist Dr. Nikolas P. Lemos, who stated: “If you’re a woman with all that T.H.C. parked in your fatty tissue, after death it leaks out and contaminates the adjacent blood, so it artificially elevates the measured concentrations in blood.” According to Dr. Lemos, the report’s findings reveal “nothing about impairment, nothing about use in jail, nothing about when she took it.”

Goldberger doubled down with the Times, countering that “even if we assume there’s been a post-mortem change, it’s not going from a negligible concentration to 18.”

While Bland’s postmortem THC levels are certainly relevant to the ongoing investigation into her death, they are absolutely not relevant to the public without appropriate context. It’s disheartening to watch Sandra Bland’s drug use become quietly, steadily politicized—the implication being, of course, that if she smoked marijuana with any kind of regularity, she deserved what happened to her.

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Image via Associated Press.