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The jury in the George Zimmerman murder trial was expected to begin deliberations as soon as Friday afternoon after the defense team rested Wednesday without the neighborhood watch volunteer taking the stand.

Judge Debra Nelson said she hoped to hand the case to the jury Friday afternoon, with closing arguments set to begin at 1pm Thursday.

The defense team used its final day of testimony to paint the neighborhood watch volunteer as a wimp who was getting pummeled when he shot Trayvon Martin in self-defense, at one point commandeering a mannequin introduced by prosecutors in order to re-enact its version of the fight.

Zimmerman did not take the stand, though his team left the option open until the last minute, with Zimmerman finally telling Judge Debra Nelson he would not testify. After O’Mara announced that he would call no more witnesses, prosecutors called the first of several witnesses back for rebuttal, beginning with Adam Pollock, owner of a kickboxing gym where Zimmerman trained prior to the incident. Like other defense witnesses, Pollock described Zimmerman as a soft weakling, likely unable to defend himself against Martin before firing the gun.

Earlier Wednesday, Zimmerman's lawyer literally flipped a prosecution witness -- a gray, foam dummy -- to re-enact the defense's version of the confrontation that ended in Martin's death, straddling the mannequin and bashing its head against the floor as stunned jurors looked on Wednesday. The mannequin was initially introduced by prosecutor John Guy during cross-examination of defense witness Dennis Root, a former law enforcement officer who testified as an expert on defensive use of force. Guy used it to show how, if Martin were straddling Zimmerman, he would have had difficulty reaching for a gun holstered at his waist.

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    After Guy wrapped up his round of questioning, lead defense attorney O'Mara stepped up.

    "May I use your doll?" asked O'Mara.

    O'Mara straddled the dummy on the floor in front of the witness stand, grabbed it by the shoulders and drove its head into the floor repeatedly.

    "Would the injuries on Mr. Zimmerman, the back of his head, be consistent with someone doing this on cement?" asked O'Mara as he slammed the flopping mannequin's head into the floor.

    "I don't think so," replied Root.

    "How about this?" asked O'Mara, continuing to bash the life-sized dummy against the floor, but placing its arm against his shoulder, as if it were resisting. "How about someone resisting the attack? Could that have come from if someone was resisting me pushing down like this?"

    Root responded, "I believe so."

    Earlier in his testimony, Root described how Zimmerman would be no match for the 17-year-old Martin in a fight.

    "Mr. Martin was a physically active and capable person," said Root, who probed both Martin's and Zimmerman's physical conditioning and fighting prowess on behalf of the defense team. "Mr. Zimmerman is an individual who is by no stretch of the imagination an athlete, and ... he would find himself lacking when compared to Mr. Martin."

    Root’s testimony jibed with prior defense witnesses who have testified that the neighborhood watch volunteer was overweight, in poor shape and not good with his fists. Root said screams heard on a 911 call, which the defense claims are Zimmerman, show "a high level of stress, a high level of fear."

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    A young mother who lived in the gated community where Zimmerman shot Martin told jurors Wednesday the neighborhood watch volunteer helped comfort her after a home invasion by two young men left her frightened.

    Olivia Bertalan said Zimmerman supplied her with a new lock for her sliding door and offered to open his own home to her after the incident, which happened about six months before Zimmerman’s fateful confrontation with Martin,. Although she said the two invaders were African-Americans in their late teens, there was no suggestion that Martin was involved. The testimony was instead apparently presented to show how seriously Zimmerman took his role as a community protector.

    Zimmerman's father, Robert Zimmerman, also took the stand Wednesday, saying it was "absolutely" his son George on the 911 call that captured the fatal confrontation.

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    Earlier Wednesday, Judge Nelson denied two requests by the defense, ruling that a computer animation that depicts the February 2012 confrontation as well as text messages that purportedly deal with fighting sent from Martin's phone will not be admissible as evidence.

    The judge seemed concerned about the animation's accuracy during arguments. While the animation can't be introduced as evidence that can be reviewed by jurors during their deliberations, defense attorneys may be able to use it during closing arguments, she ruled.

    &quotTo have an animation go back into jury room that they can play over and over again gives a certain weight to something that this court isn't exactly certain comports with the evidence presented at trial,&quot Nelson said Wednesday night.

    The judge also agreed with prosecutors' concerns about introducing the 17-year-old's text messages. But defense attorney Don West had argued the texts were relevant since they showed Martin's interest in fighting and physical capabilities.

    The Associated Press contributed to this report.