Late in the morning the prosecution called Mark Osterman, a federal air marshal who described Zimmerman as "the best friend I've ever had."
He testified that he spoke with Zimmerman both the night of and the day after the shooting. Osterman later wrote a book about his recollections of what Zimmerman told him.
Under examination by De la Rionda, Osterman said that Zimmerman told him Martin had grabbed his gun during their struggle, but that Zimmerman was able to pull it away.
That account is different from what Zimmerman told investigators in multiple interviews when he only said it appeared Martin was reaching for his gun prior to the shooting. He never told police the teen grabbed it.
"I thought he had said he grabbed the gun," Osterman said. "I believe he said he grabbed the gun."
Zimmerman has said he fatally shot the unarmed black teen in self-defense in February, 2012, because he says Martin was banging his head into a concrete sidewalk behind townhomes in a gated community. Zimmerman, 29, could get life in prison if convicted of second-degree murder.
The state argued during its opening statement that Zimmerman profiled and followed Martin in his truck and called a police dispatch number before he and the teenager got into a fight. Zimmerman has denied the confrontation had anything to do with race, as Martin's family and their supporters have claimed. A 44-day delay in Zimmerman's arrest led to protests around the nation; he was ultimately charged by a Florida special prosecutor. Zimmerman's father is white and his mother is Hispanic.