Tuesday wasn't a good day for prosecutors at the trial of George Zimmerman, the neighborhood watch captain charged with second-degree murder in the fatal shooting of Trayvon Martin in Sanford, Florida.

Forensic pathologist Vincent Di Maio, an expert on gunshot wounds, testified for the defense that the trajectory of the bullet and gun powder on Martin's body shows he was on top of Zimmerman and leaning forward when he was shot by Zimmerman.  Dr. Di Maio said he reached his conclusion after examining the autopsy, toxicology and photographic evidence.

"The most important point is the nature of the defect in the clothing and the powder tattooing," Dr. Di Maio testified. "If you lean over somebody, you would notice that the clothing tends to fall away from the chest. So the fact that we know the clothing was two to four inches away is consistent with somebody leaning over the person doing the shooting."

Zimmerman had previously said that during the confrontation, Martin had straddled him and slammed his head into a concrete sidewalk several times. Dr. Di Maio told jurors he saw six different wounds on Zimmerman—his nose, and on his forehead and the back of his head.

"The medical evidence is consistent with Mr. Zimmerman's statement that Mr. Martin was over him, leaning forward at the time he was shot," he said.

In painstaking detail, Dr. Di Maio explained how the bullet tore through the left side of Martin’s heart and right lung. He said Martin could have been conscious for 10-15 seconds after being shot—and could have talked and moved his arms due to the reserve of oxygen in his brain. Sybrina Martin had left the courtroom before the graphic testimony began, and Tracy Martin looked on intently, at times rocking slightly.

Under cross examination by the prosecution, Dr. Di Maio admitted he didn’t know how the fight began or who threw the first punch, both key—and undetermined—elements in the case.

Judge Debra S. Nelson also held an evidentiary hearing on whether to admit an animation of the fight between Martin and Zimmerman that defense attorneys want to show to jurors.

The animation was created by Contrast Forensics, a crime scene reconstruction company based in Walnut Creek, Calif., and uses the same motion capture technology used in blockbuster movies like Iron Man.

But prosecutors argued that the animation was an inaccurate depiction because it left out key details, such as the gun, and showed Martin throwing the first punch, which hasn’t been proven.

It’s highly unlikely Judge Nelson will allow jurors to view a reenactment based entirely on Zimmerman’s account of what happened that night. Judge Nelson will make a decision today.

Also on Tuesday, defense attorney Mark O’Mara grilled Sanford City Manager Norton Bonaparte Jr. about why the Martin family was allowed to hear the 911 calls, including the call with a voice screaming help, without any law enforcement—namely former Police Chief Bill Lee Jr.—in the room. Bonaparte responded that he and the Mayor of Sanford had made the decision to release the tapes to the media, and wanted the family to hear them first “as a courtesy.”

In addition, Zimmerman’s neighbor Eloise Dilligard, a Black woman who lived in the Retreat at Twin Lakes and knew both Zimmerman and his wife, said she believed the voice heard screaming for help on the 911 call was Zimmerman because he has a “light male voice.”

Dilligard said on the night of the shooting, a police officer asked her to identify either the "victim" or the "suspect." She said she recognized Zimmerman who, she said, looked severely injured.

She was billed as a key witness, but didn’t reveal any new or significant information, leading some to wonder why defense attorneys called her to testify in the first place. Did O’Mara play his own version of the “race card?”

Last night, Judge Nelson also held a hearing—without the jurors present—to determine if text messages on Martin's cell phone showing he was trying to buy or sell a gun and was involved in fights, can be allowed. Court proceedings continued until 10 P.M. The judge made no decision.

During a break in the proceedings, lead prosecutor Bernie de la Rionda told EBONY.COM that the trial "is a marathon," not a sprint. Despite the setbacks, prosecutors are still confident that Zimmerman will be convicted and can ask the judge to consider lesser charges, like manslaughter.

The defense also said it will conclude its testimony today, and the case could go to the jury by Friday.