Zimmerman contends he lost track of Martin and was returning to his car when he was attacked. But Bahadoor's testimony appeared to suggest Zimmerman was moving away from his vehicle.
O'Mara later confronted her with a post she made on Facebook in which she "liked" a petition that championed the arrest of Zimmerman following the shooting.
A Sanford police sergeant who was the second officer to arrive on the scene also testified. Sgt. Tony Raimondo said he tried to seal a bullet wound in Martin's chest with a plastic bag and attempted mouth-to-mouth resuscitation.
Bubbling sounds indicated air was escaping the teen's chest, Raimondo said. Martin was pronounced dead a short time later.
During Raimondo's testimony, prosecutors showed jurors a photo of a dead Martin face-down in the grass, another of Martin's body face up with his eyes slightly open, and a third of the bullet wound. Martin's father, Tracy Martin, walked out of the courtroom during the testimony.
Wendy Dorival, former coordinator of the Sanford Police Department's neighborhood watch program, testified how she had worked with Zimmerman to set up a watch in his neighborhood.
When asked by prosecutor John Guy if neighborhood watch participants should follow or engage with suspicious people, she said no.
"They are the eyes and ears of law enforcement," Dorival said. "They're not supposed to take matters into their own hands."
Similarly, Donald O'Brien, president of Zimmerman's homeowners association, said it was his understanding that neighborhood watch members are supposed to "stay at a safe distance" and "let the police handle it."
But Dorival said she was impressed with Zimmerman's professionalism and dedication to his community.
"He seemed like he really wanted to make changes in his community, to make it better," she said.
O'Mara told CNN on Tuesday night that defense attorney Don West was trying to bring levity to the proceedings when he began his opening statement Monday with a "knock-knock" joke, but that "it probably should have been rethought."
Asked about Martin's parents leaving the courtroom at a few difficult moments in the proceedings, O'Mara said he understood, but that both sides need to steer clear of "a maneuver or showboating" that could influence jurors.
O'Mara said he wouldn't make a decision about putting Zimmerman on the stand until seeing more of the state's case.
"In this case, they have to prove beyond a reasonable doubt not only that the crime was committed and that it was in fact a crime, but that George didn't do so in self-defense," O'Mara told CNN's Anderson Cooper. "They have to disprove self-defense beyond a reasonable doubt. If I think that they ever get to that burden, then we might consider whether we have to present any case at all."
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