SANFORD, Fla. (CBSMiami/AP) — A CBS4 exclusive interview with Trayvon Martin’s brother, Jahvaris Fulton, took center stage in the George Zimmerman murder trial Friday morning.

Jahvaris took the stand immediately after Trayvon’s mother, Sybrina Fulton, told the jury that the voice screaming for help on the 911 calls the night of the shooting was her son.

After the audio was played, prosecutor Bernie de la Rionda asked Sybrina Fulton, “Who do you recognize that to be?” She replied, “Trayvon Benjamin Martin.”

Under cross-examination, defense attorney Mark O’Mara suggested that Sybrina Fulton may have been influenced by others who listened to the 911 call, including relatives and her former husband.

O’Mara also asked Fulton hypothetically whether she would have to accept it was Zimmerman yelling for help if the screams did not come from her son. He also asked if she hoped Martin didn’t do anything that led to his death.

“I heard my son screaming,” Fulton said. “I would hope for this to never have happened and he would still be here.”

Before testifying, Sybrina Fulton posted on Twitter “I pray that God gives me the strength to properly represent my Angel Trayvon.”

George Zimmerman’s mother, Gladys Zimmerman, though, testified she recognized the voice all too well: “My son.” Asked how she could be certain, she said: “Because it’s my son.”

The testimony came on a dramatic, action-packed day in which the prosecution rested its case and the judge rejected a defense request to acquit Zimmerman on the second-degree murder charge.

The question of whose voice is on the recording could be crucial to the jury in deciding who was the aggressor in the confrontation between the neighborhood watch volunteer and the teenager.

Jahvaris also took the stand and also testified that the voice heard screaming for help on the 911 calls was also that of his brother Trayvon. But during cross-examination, O’Mara asked Jahvaris why he told a reporter last year he wasn’t sure if the voice belonged to Trayvon.

O’Mara was referring to an exclusive interview CBS4 did with Jahvaris Fulton at the end of March 2012. It’s the only time Jahvaris has spoken about his brother. The interview, which can be seen below, was conducted by then-CBS4 reporter Gio Benitez.

Jahvaris, while explaining the comment to CBS4, told O’Mara that he was shocked when he heard the 911 call.

“I didn’t want to believe it was him,” Jahvaris Fulton said.

O’Mara asked to play the television interview for jurors, but Judge Debra Nelson denied his request for the time being.

After the mother and brother testified, the doctor who performed an autopsy on Martin took the witness stand. He started describing Martin as being in pain and suffering after he was shot, but defense attorneys objected. The judge sustained the objection, and Bao was directed away from that line of questioning.

He later estimated that Martin lived from one to 10 minutes after he was shot, and the bullet went from the front to the back of the teen’s chest, piercing his heart.

“There was no chance he could survive,” Bao said.

Under cross examination, defense attorney Don West questioned why Martin’s hands weren’t covered in order to preserve evidence on his fingers and why it took three hours to remove the body from the scene. West and Bao talked over each other at several points, requiring the judge to tell everyone to speak one at a time.

With jurors out of the courtroom, Bao acknowledge he had changed his opinion in recent weeks on two matters related to the teen’s death — how long Martin was alive after being shot and the effect of marijuana detected in Martin’s body at the time of his death.

The associate medical examiner said last November that he believed Martin was alive one to three minutes. He also said Friday that marijuana could have affected Martin physically or mentally, even though he said it didn’t last year.

Nelson had ruled before the trial that Martin’s past marijuana use couldn’t be introduced, and she didn’t veer from that ruling on Friday, meaning jurors didn’t hear Bao’s opinion about the effect of Martin’s marijuana use.

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