In contrast, prosecutors argued Zimmerman showed ill will when he whispered profanities to a police dispatcher over his cellphone while following Martin through the neighborhood. They said Zimmerman "profiled" the teenager as a criminal.
Guy said Zimmerman violated the cornerstone of neighborhood watch volunteer programs, which is to observe and report, not follow a suspect.
Zimmerman's account of how he grabbed his gun from his holster at his waist as Martin straddled him is physically impossible, Guy said.
"The defendant didn't shoot Trayvon Martin because he had to; he shot him because he wanted to," Guy said. "That's the bottom line."
But to invoke self-defense, Zimmerman only had to believe he was facing great bodily harm, his attorney said. He asked jurors not to let their sympathies for Martin's parents interfere with their decision.
"It is a tragedy, truly," O'Mara said. "But you can't allow sympathy."
As people watch the Zimmerman trial, one of the people who seems to have taken the hardest line in the case has been Judge Debra Nelson. Channel 4 watched some of the exchanges between Nelson and the lawyers involved in the Zimmerman case.
"This case could have easily gotten out of control," explained defense attorney Gene Nichols. "That's why Judge Nelson has taken some of the hardest line she ever has before."
Nelson has been on the bench since 1999. She replaced a judge in the Zimmerman trial who the defense claimed was biased against Zimmerman, but that doesn't mean she hasn't had her own clashes with the defense.
"You have a minimum of 7 to 8 lawyers, not to mention 3 to 4 cameras. Full of family, full of lawyers, it would've been difficult to handle this any other way," said Nichols.
At one point during the trial, Judge Nelson gets up and walks out of court.
"Mr. O'Mara knows already that this situation has gotten out of control," said Nichols.
With the verdict drawing near, police and city leaders in Sanford and other parts of Florida said they have taken precautions for the possibility of mass protests or even civil unrest if Zimmerman, whose father is white and whose mother is Hispanic, is acquitted.
There were big protests in Sanford and other cities across the country last year when authorities waited 44 days before arresting Zimmerman.
About a dozen protesters, most of them from outside central Florida, gathered outside the courthouse as the jury deliberated. Martin supporters outnumbered those for Zimmerman.