Is really coming down to the wire tonight in the trial that is both captivating and polarizing America the defense rested today in very soon. The jury of six women will decide whether George... See More
Is really coming down to the wire tonight in the trial that is both captivating and polarizing America the defense rested today in very soon. The jury of six women will decide whether George Zimmermann will go free. -- spend the rest of his life in prison perhaps whatever they decide is likely to enrage millions of Americans police in Florida are bracing for the worst. And ABC's Matt Gutman is on the story. They made a decision as to whether or not. One intensifying -- objective question I think that's. Overall the tensions boiled over in court today as judge Deborah Nelson demanded that George Zimmerman -- the question on. Everyone's minds for months will he finally take the stand in his own murder trial. Mr. Zimmerman have you made -- decision as to whether or not you want to testify in this case not not at this time okay later in the day she asked again. Finally he gave his answer and what is your decisions are. After consulting with the council not to tell us. He didn't testify but it was the most he'd spoken in court the 21 days since this contentious trial began and with that the defense rested its case. Seemingly confident. Established of the six person all female jury that when the former neighborhood watchman shot and killed seventeen year old -- -- -- February 2012. It was an act of self defense. The jury's already heard him give his version of events right so doesn't make a lot of sense for him to get on the witness stand the -- not gonna hold it against him. If he doesn't. In a dramatic -- court. The prosecution presented a man -- during the questioning the defense witness in this wrote that law enforcement officer. -- where the defendant described to his best friend that. When he slid down the defense slid down. That. -- -- -- -- his brother's office. We -- that. He's now. Some curious tourists and even the defense team crying -- next to see some -- and stood up there where they got me now. Now -- would be behind your loved like okay. Then the defense had its turn -- show and tell. Murdered the dog who. The defense claims Zimmerman shot Martin's self defense says the seventeen year old pounded his head into the pavement. The injuries. Mrs. Simmons factories that's -- where. -- -- -- -- -- -- W resisted the attempt the injuries to two lacerations to some that disagree with resisting the received. -- I believe so it was one of many theatrical moments in a trial. That has captivated the nation for weeks the defense scored an early victory when he grilled prosecution's star witness Rachel -- -- A friend of Martins who was on the phone with him just moments before it was -- can be. She testified -- Martin was scared that night but defense attorney Don west went after her credibility. For all you know treatment -- smashing -- Zimmerman in the face is what you actually her. -- yeah -- just earlier today. Now. Then another blow for the prosecution. Lead investigator Chris -- -- Whose testimony seemed to further bolster the defense's case stated -- -- story about the incident that night. Was remarkably Cisco. -- is -- anything else in this case where you got the insight that he might be atop a lot. Let's -- the case is not without gaps notably from defense attorney Don west whose opening argument began improbably enough. -- -- -- Who's there. George -- George Zimmermann who. All right good. You're on the jury and then he drew criticism for that relentless cross examination -- Martin's friend went to John -- that's -- Even exposing her limited literacy. Can you read any of the words on it. I don't understand. Carson. And it. The day after that appearance this stealthy went viral. West posing with his daughters one of whom posted its snapshot two -- to Graham. Along with the caption. We -- stupidity celebration -- with the hash tag. Daddy killed. Was later apologized for an incident that triggered outrage emotion from the prosecution for an inquiry. -- west said deference to his family attention -- long hours apparently taking their told the attorneys Tuesday night -- procedural hearing about. This 3-D animation turned into a marathon -- -- we're hearing from attorneys attacking each other and look -- defense attorney Marco Marek. Almost physically restraining west. And yeah. -- -- -- And physically. It's 10 o'clock at night we started this morning. Full days every day. We -- depositions. It. The prosecution strategy was to hammer away -- Zimmerman credibility highlighting any inconsistencies during the trial there are two people involved here. One of homestead -- alliance. And one of the crucial questions at -- who was heard yelling for help on the -- 911 calls from the night of the shooting but you know whose voice that is. In the background screening. -- the defense called a parade of witnesses friends of George Zimmerman to the -- all of them said they could make out the same points. I thought -- was George there's absolutely no doubt in my mind. There's -- person. -- -- did not have a better feel and understand. But the jury also heard emotional testimony from -- -- Morton's parents. Disagree if you recognize that can be turned. John Benjamin Martin I was listening to -- my son's. Last preference known most listened to his life began taking. I was coming trying to. Come to grips. -- while I was here no moral. Closing arguments in the trial will begin tomorrow and in the case will go to victory closing arguments are going to be the key. To this trial this trial is all about summations. And putting that picture in front of the -- regardless what they decide Denver police chief Cecil Smith is preparing for -- potentially hostile response from the community what. Percentage of your police force is going to be ready in anticipation of whatever happens our entire -- part. Everybody personal vacations there's no for a -- -- here you're all sick. You have to be physically off -- you'll be working at some point. -- -- -- -- -- -- stand together as one no cost no gun. And it's not just Sanford that's bracing for the worst in Broward County Florida the sheriff's office releasing this PSA trying to encourage residents to stay peaceful. The event of any -- -- And if the verdict does go his way Zimmerman for one -- hoping that everyone will follow that advice. He's very worried about his safety personal safety going forward. Because those same people who put tended to fear and hatred. Leading up to this trial probably not come to accept -- -- court. I'm Matt Gutman for Nightline. ABC news in Sanford Florida.
This transcript has been automatically generated and may not be 100% accurate.