Jurors in the George Zimmerman murder trial will be able to hear defense testimony that Trayvon Martin had small amounts of marijuana in his system at the time he was shot to death in February 2012.

In a ruling this afternoon, Judge Debra Nelson rejected a prosecution request to bar a portion of a toxicology report that revealed Martin had been smoking pot at some point prior to Zimmerman killing him with a single gunshot to the heart.

Nelson, who previously granted a prosecution motion to limit testimony about the government toxicology report, reversed herself in the wake of last Friday’s testimony by the medical examiner who performed the Martin autopsy. Zimmerman’s lawyers will apparently introduce findings from the toxicology report through the testimony of a defense witness or via a proffer agreed upon by both sides.

Medical examiner Shiping Bao told jurors that he had changed his opinion with regard to whether Martin’s marijuana level could have affected his physical or mental state on the night of the shooting. Bao initially concluded that the amount of THC (tetrahydrocannabinol) in Martin’s blood would not have had any impact on the 17-year-old's behavior.

However, during his testimony last week, Bao referenced Martin’s THC level, noting that “Marijuana could have no effect or some effect.” 

In Zimmerman’s call to a non-emergency police line, he told a dispatcher that a person he was observing (who turned out to be Martin) appeared to be “on drugs.”

Zimmerman’s lawyers have previously argued that they should be allowed to introduce evidence of Martin’s drug use, pointing to text messages appearing to refer to his use of marijuana. Additionally, the attorneys also unsuccessfully argued for the admittance of a pair of photos of pot plants that were found on Martin’s cell phone. Other recovered images showed a handgun and Martin blowing smoke from his mouth (as seen above).