The acrimonious hearing followed the testimony of renowned forensic pathologist Dr. Vincent Di Maio, who seemed to back up Zimmerman's account that Trayvon Martin was on top and leaning over the former neighborhood watch captain when Zimmerman shot the teen.
Di Maio, who was paid $400 an hour by the defense, said that the pattern of powder burns on Martin's sweatshirt and skin indicated that his shirt was two to four inches away from Martin's chest when he was shot, suggesting, he said, that Martin was hovering or leaning over Zimmerman.
"The medical evidence is consistent with his statement," Di Maio told the Florida court.
Di Maio said that the pattern of powder burns on Martin's sweatshirt and skin indicated that the shirt was two to four inches away from Martin's chest when he was shot by Zimmerman.
"Mr. Martin was over him, leaning forward," he said.
"If you are lying on your back your clothing is going to be against your chest," said Di Maio. "The clothing is consistent with someone leaning over the person doing the shooting."
Zimmerman maintains that he shot the teenager in self-defense during an altercation in which the teen had knocked him down, was hovering over him and banging his head into the concrete sidewalk.
Di Maio, who was put on the stand by Zimmerman's defense attorneys, contradicted the testimony of the prosecution's expert, Dr. Shiping Bao, on another point. Bao told the court earlier in the trial that the bullet pierced Martin's heart and would have instantly incapacitated Martin, disputing a key assertion from Zimmerman that the teen sat up and said "You got me" after he was shot.
The prosecution said, at one point, with the jury out of the room, that Bao's testimony raised questions about Zimmerman's credibility.
Jurors furiously took notes as Di Maio, who said he reviewed the autopsy, toxicology, and medical records of both men, said that Martin most likely died within one to three minutes after the shooting. Bao had told the jury Martin could have lived for a painful 10 minutes after being shot.
Zimmerman's legal team also tried to their bolster contention that it was Zimmerman on his back during a fight with Martin on top of him.
Di Maio looked at pictures of Zimmerman's injuries and said that it was possible to receive severe head injuries without visible external injuries.
When asked if the abrasions of the back of Zimmerman's head could have been caused by concrete, Di Maio responded, "Yes."
Looking through photos of Zimmerman's injuries on his face and head, Di Maio told the jury, "You have six identifiable injuries."
Earlier Dr. Valerie Rao testified for the prosecution that Zimmerman was struck as few as three times during the fight with Martin and that his head slammed on the concrete once.
Rao called Zimmerman's injuries "insignificant" and "non-life-threatening."
One of the last witnesses in Zimmerman's murder trial testified that the screams heard on 911 calls moments before Martin was shot and killed came from Zimmerman.
Zimmerman's lead defense attorney, Mark O'Mara, said that he expected to rest his case Wednesday.
Before concluding for the day, he had Eloise Dilligard, an African-American neighbor of Zimmerman, testify from her home on a large screen in the courtroom.
Dilligard asserted that the voice screaming for help in the background of 911 tapes was Zimmerman. Her testimony could be significant in the racially charged case.
Who is screaming for help has been a major contention in the trial since prosecutors claim the voice is that of Martin, and defense claims it is Zimmerman.
Determining that it was Zimmerman's voice would bolster his self-defense claim.