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.