Medical Examiner: Pot 'Could Have' Altered Trayvon Martin's State Of Mind

Reuters/Gary W. Green/Pool Volusia and Seminole County associate medical examiner Shiping Bao MD testifies during George Zimmerman's trial in Seminole circuit court in Sanford, Florida July 5, 2013. Shiping Bao, the medical examiner who autopsied Trayvon Martin, testified with jurors gone from the courtroom Friday that pot in the teen's system "could have" altered his mind and body the night he died.

Bao apparently changed his mind, as he previously said the THC in Martin's blood wouldn't have affected his physical or mental state the night he was killed by George Zimmerman.

The defense in Zimmerman's second-degree murder trial wants a jury to hear Bao's latest testimony, but the judge overseeing the case denied that request Friday.

Zimmerman says he shot Martin in self-defense in February 2012, so any evidence that Martin had an altered state of mind could help his case.

If the prosecution had withheld the medical examiner's change-of-heart from the defense, they could be in serious violation of the law. Bao, however, said he didn't tell Bernie De La Rionda, lead attorney for the state, about his new thoughts on the THC in Martin's blood. The two met the day before to discuss Bao's Friday testimony.

Judge Debra Nelson previously ruled that neither side could introduce Martin's marijuana use into court.

During a Richardson hearing, used in court to determine if protocol was followed when exchanging evidence, Judge Debra Nelson found no violation and ruled the THC testimony still won't be allowed in court.