George Zimmerman in police custody, faces second-degree murder charge in Trayvon Martin shooting

(CBS/AP) SANFORD, Fla. - A special prosecutor in Florida announced Wednesday afternoon that George Zimmerman will be charged with second-degree murder in the shooting of unarmed teen Trayvon Martin.

Pictures: Trayvon Martin shooting

Special prosecutor Angela Corey also confirmed at the 6 p.m. news conference that the 28-year-old Zimmerman is in custody, but would not say where. She said that he will be in court within 24 hours.

Zimmerman has admitted to shooting 17-teen-year-old Martin in February, but claims he acted in self-defense. He was not arrested partly because of Florida's so-called "stand your ground" self-defense law, which gives people wide latitude to claim self-defense in altercations.

Corey says that authorities did not come to their decision to charge Zimmerman with second-degree murder lightly, nor was it based on public pressure. The charge carries a maximum sentence of life in prison. Second-degree murder is typically charged when there is a fight or other confrontation that results in death and where there is no premeditated plan to kill someone.

Martin's mother Sybrina Fulton said earlier she knows "justice will be served" in her son's death.

Attorney Benjamin Crump said earlier that the family wants communities nationwide to remain calm in response to the prosecutor's decision. "We don't need anybody taking these matters into their own hands," Crump said.

Attorney General Eric Holder said earlier today that he would take appropriate action if evidence of a civil rights crime is found in the shooting. The Justice Department launched an investigation of the Martin killing three weeks ago.

Complete coverage of the Trayvon Martin case on CBS News