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The mothers of both Trayvon Martin and George Zimmerman testified Friday it was their own son's voice calling for help on a taped 911 call in a dramatic day of testimony that saw the prosecution rest and the defense begin its case in Zimmerman's murder trial.

After Judge Debra Nelson ruled against a defense motion for acquittal late Friday afternoon, the prosecution announced it was resting and the defense began by calling Zimmerman's mother, Gladys.

She testified the voice heard screaming for help on the 911 call was her son's and she knew it was him "because he's my son." The recording was made during a fight between Zimmerman and Martin minutes before the neighborhood watch volunteer shot the teen.

Zimmerman's uncle, Jorge Meza, a deputy with the Orange County Sheriff's Office, then testified that he overheard the 911 screams while watching television and, " It was Jorge screaming for his life."

Court was then recessed until Monday morning.

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    Earlier Friday, Sybrina Fulton, Martin's mother, testified that her 17-year-old son could clearly be heard on the tape recorded Feb. 26, 2012.

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    After the 911 audio was played, prosecutor Bernie de la Rionda asked Fulton, "Who do you recognize that to be?"

    "Trayvon Benjamin Martin," she replied.

    Defense attorney Mark O'Mara suggested during cross-examination that 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. O'Mara 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."

    Earlier Friday, Fulton posted on Twitter: "I pray that God give me the strength to properly represent my angel Trayvon."

    Trayvon's brother, Jahvaris Fulton, 22, also testified Friday that he recognized Trayvon's voice on the 911 calls.

    O'Mara then asked Trayvon's older brother why last year he had told a reporter that he wasn't sure if the voice belonged to Martin.

    "I didn't want to believe it was him," Jahvaris Fulton testified.

    Zimmerman’s father, in contrast, has said the screams were from his son rather than Martin. The screams are considered to be crucial pieces of evidence because they could determine who was the aggressor in the confrontation. An FBI expert testified earlier in the week that a person familiar with a voice is in the best position to identify it.

    Shiping Bao, who performed Martin’s autopsy a day after he was killed, testified that the cause of death was a gunshot wound to the chest. The manner of death was a homicide, he said.

    Bao testified that Martin was in pain and suffered for up to 10 minutes after being shot by Zimmerman. The fatal bullet went from the front to the back of the teen's chest, piercing his heart.

    "There was no chance he could survive," Bao testified.

    Under questioning by defense attorney Don West following Friday’s lunch recess, Bao said he changed his opinion regarding the length of time Martin lived after being shot from his original estimate during a deposition he gave in November of 1 to 3 minutes to up to 10 minutes. He changed his opinion following another autopsy roughly three weeks ago that was “very similar” to that of Martin’s, Bao testified.

    Bao also testified that the marijuana found in Martin’s system coul have had no effect or some effect in the confrontation with Zimmerman.

    When asked if Martin would be able to move his arms or hands after being shot, Bao responded that “only one person in this court knows.”

    On Wednesday, an expert witness testified that none of Zimmerman's DNA was found under the fingernails of Martin, despite defense attempts to portray Zimmerman as only firing his gun in self-defense.

    Crime lab analyst Anthony Gorgone also testified that two different DNA profiles were found on the pistol grip. One was Zimmerman's but the other could not be identified. However, Gorgone said he was able to determine that it did not match Martin's DNA sequence.

    Prosecutors spent most of Wednesday's proceedings painting Zimmerman as a police wannabe, amid testimony that featured technological glitches, forensic evidence and a prosecution witness who greeted Zimmerman from the stand.

    Zimmerman faces life in prison if convicted of second-degree murder. The state argued during its opening statement that Zimmerman profiled and followed Martin in his truck and called a police dispatch number before he and the teen got into a fight.

    Fox News' Joshua Rhett Miller, Perry Chiaramonte, Serafin Gomez and The Associated Press contributed to this report.

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