Five friends of George Zimmerman testified on Monday they heard his voice calling for help in the background of a 911 emergency call the night he shot Trayvon Martin, backing his claim he killed the unarmed black teenager in self-defense.
The second-degree murder trial of the neighborhood watchman could turn on the disputed identity of who was calling for help on the night of Feb. 26, 2012, when Zimmerman, 29, killed Martin, 17, triggering a national debate on race and guns in America.
Martin's mother and brother previously told the jury of six women they recognized the voice of Martin, when the prosecution concluded its side of the case on Friday. They were followed by Zimmerman's mother and uncle, who testified for the defense it was their relative pleading for help.
As the defense case neared its end, it remained uncertain whether Zimmerman, who faces life in prison if convicted of second-degree murder, would choose to testify.
Police in Sanford, Florida, at first decided against arresting Zimmerman, who is white and Hispanic, accepting his claim of self-defense. That ignited protests and cries of racial injustice in Sanford and major cities across the United States, as the case came to reflect what many saw as unequal treatment of African Americans before the law.
It also drew attention to Florida's "Stand Your Ground" self-defense law that police cited in initially declining to arrest Zimmerman, who was licensed to carry a concealed weapon that was fully loaded with hollow-point rounds.
The screams were recorded in the background of a 911 call placed by a neighbor who called to report two men fighting. The screams end when a shot rings out from Zimmerman's Kel Tec 9mm pistol.
An FBI voice recognition expert testified last week the screams were too short and the audio of too poor quality to apply standard scientific voice identification techniques, saying the next best method to identify the voice was by a listener who knew the person his whole life and had heard him in various emotional states speaking, screaming and yelling.
Defense lawyers followed up on Monday by calling five more witnesses - all friends and supporters of the defendant - who said it was Zimmerman. Among them was John Donnelly, who said Zimmerman was "like a son" and who donated $3,000 to Zimmerman's defense and bought him $1,700 worth of clothes for his trial.
As a medic in the Vietnam War in the 1960s, Donnelly said, he developed an ability to recognize which of his fellow soldiers was screaming for help.
"And I wish to God I didn't have that ability to understand that," Donnelly said.
Two others were Mark and Sondra Osterman, a husband and wife who wrote a book about Zimmerman and agreed to donate the proceeds to their friend.
"Yes, definitely, it's Georgie," Sondra Osterman said.
"I thought it was George," Mark Osterman said later. "It just sounded like George."
Mark Osterman, a federal air marshal and long-time law-enforcement officer, also told the jury he advised Zimmerman to buy the Kel Tech 9mm and helped train him to use it at a shooting range.
Earlier on Friday, prosecutors asked Seminole County Judge Debra Nelson to block the jury from seeing an animated re-enactment of the shooting, saying the video distorted the events of that fatal encounter.
The defense commissioned the re-enactment animation, employing assistants who acted out the struggle while wearing special suits used for motion-capture video.
State prosecutors argued the video failed to show the gun and showed details of the fatal struggle based on the animator's "approximations," including the number of blows during the fight and how each body reacted to those blows, among other objections.
Nelson has yet to rule on whether the jury could see the re-enactment of the events.
Zimmerman remained free for 45 days after that, until a special prosecutor later brought the charge of second-degree murder.