Updated

A probable cause affidavit filed in the second-degree murder case against George Zimmerman provides some insight into why Florida special prosecutor Angela Corey chose to charge Zimmerman in the fatal shooting of unarmed 17-year-old Trayvon Martin.

The four-page document prepared by prosecutors says that "Zimmerman confronted Martin." Zimmerman had told police that he shot Martin in self-defense, fearing for his life after Martin punched him in the nose, knocked him down and then banged his head on the sidewalk.

The affidavit alleges Martin was "profiled by George Zimmerman." It also states Martin was "unarmed and was not committing a crime."

The affidavit says Martin's mother identified screams heard in the background of a 911 call as her son's. There had been some question as to whether Martin or Zimmerman was the one calling for help.

Click here to read the full affidavit of probable cause.

More On This...

    And prosecutors interviewed a friend of Martin's who was talking to him by phone just before the shooting. The affidavit says Martin told the friend he was being followed and was scared.

    Martin tried to run home, the affidavit says, but was followed by Zimmerman. "Zimmerman got out of his vehicle and followed Martin," the affidavit said.

    It also notes that "Zimmerman disregarded the police dispatcher" who told him to stop pursuing, and he "continued to follow Martin, who was trying to return to his home."

    Zimmerman appeared in court for the first time Thursday after being arrested and charged on Wednesday. He faces a minimum sentence of 25 years in prison if convicted of second-degree murder, which carries a maximum penalty of life in prison.

    Judge Mark E. Herr said he found probable cause to move ahead with the case and that an arraignment would be held on May 29 before another judge.

    Mark O'Mara, Zimmerman's attorney, said his client would plead not guilty and invoke Florida's so-called "stand your ground" law, which gives people wide latitude to use deadly force rather than retreat during a fight.

    The Associated Press contributed to this report.