The prosecutors in the George Zimmerman / Trayvon Martin case made a terrible tactical decision to pursue the case by presenting a contrasting interpretation of facts, and letting jurors decide which one made more sense. The problem with this: Criminal trials require reasonable doubt, not a preponderance of evidence.
If you are presented with two possible scenarios and are told to discern the truth between the two, even if you think the prosecutor's case is more likely, the fact that there is some possibility to the defense's case, makes it impossible to rule in favor of the prosecutor. If it was a civil lawsuit, the plaintiff's side would win; in a criminal case, the defense wins. The Martin family settled months ago, so there will be no trial.
The prosecutor surely didn't plan it exactly this way. They probably planned to question Zimmerman's truthfulness directly. But the defense never brought him to the stand to testify, and instead used videos from his interviews with police, as a means to present the Zimmerman scenario, then extracted testimony from witnesses and police officers to support the possibility that the Zimmerman scenario could have occurred. The prosecution could only question the likelihood of the Zimmerman scenario by attacking the quality of interpretation of witnesses and officers.
Instead of chasing Murder 2, the prosecution should have solely pursued Manslaughter:
Florida Statute 782.11 Unnecessary killing to prevent unlawful act.—Whoever shall unnecessarily kill another, either while resisting an attempt by such other person to commit any felony, or to do any other unlawful act, or after such attempt shall have failed, shall be deemed guilty of manslaughter, a felony of the second degree.
Yes, they put manslaughter on the table for the jury to consider, but that was after the fact when they realized they might not get a Murder 2 conviction. The prosecutor's case was aligned to present Murder 2, when the case they had was Manslaughter all along.
Zimmerman pursued Martin in his vehicle. He got out of his vehicle and followed him over several minutes -- he was out of breath in the audio recording with 911. In his mind, he was pursuing someone who was in the middle of committing an illegal act, even though he wasn't exactly sure what the illegal act was. He brought his gun with him in pursuit of Martin. He discharged it, when involved with a confrontation with Martin.
If Zimmerman hadn't pursued Martin on foot, he wouldn't have been placed in the situation where he killed Martin. That is an unnecessary kill, of Zimmerman's own making.
But you see, the prosecution never focused on this narrative. They failed to achieve a conviction because they seized on the incorrect theory that Martin was murdered out of malice.
Now there's talk about pursuing federal civil rights prosecution. The problem still remains however, that there are two sides of equivalent interpretations of the facts -- that balance hasn't changed beyond a reasonable doubt.
Update: I forgot to address Florida Statute 776.013, aka "Stand Your Ground". Zimmerman's narrative was based on his ability to defend himself. However, if 776.013 applied to all people who purposely moved their "ground" to pursue suspected criminals, by invoking 776.013, it would fully invalidate 782.11 100% and give complete protection to vigilantes.
I cannot believe, and it would be an improper assumption, that the Florida legislature meant to completely invalidate 782.11 by creating an overwhelming conflict between two laws. If their intention was to invalidate 782.11, they would have simply repealed that law.
I also cannot believe that the Florida legislature meant to legalize vigilantism.
But again, the prosecution never bothered to attack this conflict head on because, well...they were stuck on trying to prove Murder 2. So like I said, it was a terrible tactical move by prosecutors. If they had pursued Zimmerman on 782.11, they could have appealed the jury's decision based on conflict of intrajurisdictional laws. With an acquittal of Murder 2, prosecutors have no basis to appeal the jury's decision.
Second Update:
This makes a lot of sense. The prosecutors may have deliberately botched the trial. I had wondered about why they waited a full day to claw back portions of an officer's testimony. Once something is spoken in a court room, no matter what a judge says, the thought is already placed in the back of your mind.