The prosecutors in the trial of George Zimmerman will reveal a star, mystery witness today—the young woman with whom Trayvon Martin was talking in the last few minutes of his life. Known at Witness #8, the teenager will testify about what Martin told her the night that he was shot by Zimmerman.

The 17-year-old Martin was unarmed at the time that 29-year-old Zimmerman shot him. Martin told the young woman that he noticed Zimmerman was watching him in the gated community in Sanford, Florida. When Martin was visiting Retreat at Twin Lakes, Zimmerman was serving as a neighborhood watchdog. In written testimony, Witness #8 (also called Rachel) has described Martin as frightened and attempting to escape Zimmerman, as she urged Martin to run.

The shooting of Trayvon Martin, a black teenager, by Zimmerman, who identifies as Hispanic, prompted civil rights protests and debates throughout America, especially after the police delayed arresting Zimmerman for 44 days after the shooting. In 2005, Florida passed a "Stand Your Ground" law, which allows people who fear for their lives to use deadly force without having to retreat from the confrontation.

Zimmerman's defense attorney, Don West, started the trial yesterday with a "knock-knock" "joke" that "fell flat": "Knock knock. Who's there? George Zimmerman. George Zimmerman who? Good, you're on the jury." West went on to attempt to portray his client as "viciously attacked" by Martin.

Zimmerman has pled not guilty to the second-degree murder. If he is convicted, he would face life in prison. In order to convict Zimmerman, the prosecution must convince jurors that he acted with "indifference to human life" and "ill will, hatred, spite, or evil intent."

[image of Trayvon Martin's parents via AP]