Video via The Orlando SentinelVideo via The Orlando SentinelThis morning Judge Debra Nelson made two rulings favoring the prosecution in George Zimmerman's murder trial. Nelson said the defense may not introduce an animated re-enactment of the fight between Zimmerman and Trayvon Martin as evidence, although it can be used for illustrative purposes while making an argument. She also excluded text messages recovered from Martin's phone that discussed fighting, which the defense wanted to introduce as evidence that Martin had experience in physical altercations.

On Monday, by contrast, Nelson said she would allow the defense to introduce evidence that Martin had trace amounts of THC in his blood when he died. So far the defense has not taken advantage of that ruling. When forensic pathologist Vincent De Maio testified yesterday, for example, the defense did not ask him about Martin's marijuana consumption. That is probably just as well, since the amount of THC found in Martin's blood—1.5 nanograms per milliliter—was so small that it cannot plausibly be cited as a source of impairment or a factor in how Martin responded to Zimmerman. By comparison, both Colorado and Washington now have a cutoff of five nanograms (more than three times the level in Martin's blood) for driving under the influence of a drug, and even that level is not a reliable indicator of impairment. In addition to being irrelevant, talking about Martin's pot smoking would run the risk of alienating the jury by appearing to impugn the dead teenager's character.

Today the defense is presenting testimony from private investigator Dennis Root, who among other things has noted that Martin was in better physical shape and more athletic than Zimmerman. On Monday a trainer who worked with Zimmerman at a gym where he was a member for about a year, Adam Pollock, likewise emphasized that Zimmerman was a "rank beginner" in grappling and boxing, working hard and losing weight but never acquiring skills that would be useful in a fight. In short, the defense is portraying Zimmerman as a pudgy pussy in an effort to counter the impression that he was "twice the size" of Martin (as a reader erroneously claimed in response to my column today) and therefore could not have reasonably feared serious injury or death as a result of an assault by the teenager. At the time of the shooting, Zimmerman was about 20 pounds heavier than Martin, who was four inches taller. It is not hard to imagine how a younger, fitter person could have gotten the better of him in a fight.

Speaking of which, De Maio yesterday testified that evidence from Martin's clothing and his chest wound indicated Martin was bending over Zimmerman when he was shot. The best that the prosecution could do to counter that testimony during cross-examination was to ask whether it was possible that Martin was getting off Zimmerman at the moment he was shot. Prosecutor Bernie de la Rionda also asked Di Maio whether the scrapes on the back of Zimmerman's head could have been caused by a tree branch instead of contact with a concrete sidewalk, as Zimmerman claims. Yes, said Di Maio, but "you'd have to have a tree branch there, and I didn't see any." Add to the medical evidence the fact that the back of Zimmerman's jacket was wet and covered with grass, and you have a pretty solid basis for believing the neighbor who reported seeing Martin on top of Zimmerman right before the gunshot and doubting the two neighbors who suggested that Zimmerman was on top at that point.