Lots of buzz erupted on Twitter about the testimony of prosecution witness Jonathan Good in the murder trial of George Zimmerman, and it’s not difficult to understand why. Good, who witnessed the fight but apparently not the fatal gunshot that killed Trayvon Martin, not only contradicted the prosecution’s previous witness, but bolstered Zimmerman’s self-defense argument, even in direct examination (video via Jim Hoft):

A man who said he witnessed George Zimmerman’s shooting of Trayvon Martin told a court today that what he saw indicated that Martin was on top of Zimmerman moments before Zimmerman shot and killed Martin. The testimony of John Good contradicted that of a neighbor who told the Florida court Thursday Zimmerman was on top of Martin in those critical seconds before the fatal shot was fired. … “Could you describe who was on top and who was at bottom,” asked prosecutor Bernie de la Rionda. “The color on top was dark and the color at bottom was…red,” responded Good referring to the men’s clothing. At another point he told the court that the person on the bottom had “lighter skin color.” Zimmerman is a white Hispanic who was wearing a red and black jacket that night. Martin, who was black, was wearing a dark sweatshirt. He also said, “The person on the bottom, I could hear a ‘Help.'” Under cross examination by Zimmerman’s lawyer, Good said he believes he saw Martin on top punching Zimmerman “MMA style,” a reference to mixed martial arts.

Some people on Twitter wondered why the prosecution called Good at all, given the damage it does to the case they want to make of second-degree murder. Generally speaking, the prosecution has an obligation to address all of the evidence in a case, not just the pieces they like best. Practically speaking, the prosecution knew that the defense would call Good to the stand if they did not, so the best strategy would be to take the surprise out of the testimony, and hope that a direct examination could possibly put this in a better context. After all, they had another eyewitness testify that the positions were reversed, and the prosecution might hope that the jury would find that witness more credible than Good — although that looks like a long shot, given Good’s performance on the stand so far. Bear in mind that the prosecution has not yet rested, and may have more witnesses that will incorporate Good’s testimony into the overall theory of their case. It’s usually a mistake to take too much out of context in trial testimony while the case is still unfolding.

Still, this makes the question of the charges even more acute. The state could have charged Zimmerman with manslaughter and argued that he used deadly force without just cause, rather than go with a second-degree murder charge that requires some act of malice or “depraved mind.” If Good convinces the jury that Zimmerman was receiving an “MMA-style beating” when he pulled the pistol and fired, then the only verdict left is acquittal of second-degree murder. Even the conflicting witness testimony could be enough to produce a reasonable doubt in the minds of jurors.

This has the appearance of over-charging by the prosecution, and that raises its own questions about motives involved in making that decision.