The special prosecutor investigating the death of Florida teenager Trayvon Martin announced Wednesday evening that George Zimmerman, who told police he shot Martin in self defense, has been charged with second-degree murder.

Zimmerman will plead not guilty to the charges, according to his attorneys. He faces up to life in prison if convicted.

Zimmerman, who has been in hiding for weeks, is in police custody. Special prosecutor Angela Corey said during a news conference in Jacksonville, Fla., that she would not reveal where Zimmerman was out of concern for his safety. “He is within the custody of law enforcement officers in the state of Florida,” Corey said.

The murder charge indicates prosecutors plan to prove Zimmerman shot Martin with malice, though without premeditation. A manslaughter charge would have required prosecutors to prove only that Zimmerman acted unlawfully and with criminal negligence in shooting the teen.

“The difference between murder and manslaughter is your mental state,” said Mark Geragos, a Los Angeles defense attorney, who is not connected to the case. “To elevate it to murder, you have to have the element of malice.”

In Florida, a grand jury must be convened before issuing first-degree murder charges. On Monday, Corey announced that she would not convene a grand jury, which had been scheduled for Tuesday, in the Martin case.

Zimmerman, 28, shot and killed 17-year-old Martin Feb. 26 in a gated community in Sanford, Fla., where Martin was visiting his father and his father’s girlfriend. Zimmerman served as captain of the neighborhood watch and told police that he shot Martin in self-defense after the teen attacked him. Martin was unarmed at the time of his death, according to police.

On the night of the shooting, Zimmerman was questioned at the police station, but released shortly afterwards. Sanford Police Department investigated and determined there was not enough evidence to refute his claims of self-defense.

The case became a flashpoint in the ongoing national debate over racial profiling and gun control. Attorneys representing Zimmerman have called the shooting a clear case of self-defense under Florida’s Stand Your Ground law, which gives citizens broad latitude to use deadly force against an attacker if they believe their life is at risk.

Corey called the Stand Your Ground law a “tough” defense to counter, but said her office would fight it if it became an issue at trial. To prevail, the prosecution would have to demonstrate that Zimmerman’s account of events is false, then present the jury with a compelling alternative to the altercation, experts said.

“They will go very hard at (Zimmerman’s) credibility,” said Paul Callan, a defense attorney and former New York prosecutor who is not connected with the case. “This is how prosecutors customarily disprove bogus self-defense claims.”

Martin’s death and subsequent handling of the investigation also sparked national outrage and calls for Zimmerman’s arrest. From the start, Martin’s family and attorneys questioned the impartiality and thoroughness of the police investigation into the teen’s killing.

Law enforcement experts said that Sanford police made key errors early in the investigation and made crucial decisions before important evidence was gathered.

Martin’s cell phone records were not immediately checked. Investigators did not talk with key witnesses for more than a week. While police conducted a criminal background check on Martin, as well as post-mortem drug and alcohol tests, Zimmerman was not subjected to similar tests. It was learned later that Zimmerman was arrested in 2005 for assaulting a police officer.

During the news conference Wednesday, Corey criticized leaks of confidential details about the case that appeared to bolster Zimmerman’s self-defense claims. “So much information on the case got released that never should have been released,” Corey said.

The announcement of the charges comes a day after Zimmerman’s previous attorneys withdrew their counsel, saying they lost contact with him and that he repeatedly ignored their legal advice. They said Zimmerman reached out to Corey’s office directly and had an off-the-record conversation with the Fox News host Sean Hannity without their knowledge.

Trayvon’s parents, Tracy Martin and Sybrina Fulton, solemnly watched Wednesday’s news conference in Washington on a small television. As Corey read the charges, the slain teen’s parents held hands and watched. “Thank you, Lord,” said Benjamin Crump, the family’s attorney as he patted Martin’s knee.

After the charges were announced, Fulton said she was thankful for the outpouring of public support. “I just want to speak from my heart to your heart, because a heart has no color,” she said. “It’s not black, it’s not white, it’s red, and I want to say thank you from my heart to your heart.”

The Rev. Al Sharpton, one of the more prominent supporters of the Martin family, said the case would not have progressed without “the nameless, faceless people, black, white, Hispanic and Asian … who said ‘take another look at this’.”

“People took their time and money, and stood up and said that that could be my son, that could be my grandson, and because of that this got a second look,” he said. “Even conservatives on the other side of the political spectrum said we’re going to take another look.”

But Sharpton stressed the importance of continuing to seek justice. Zimmerman, Sharpton said, “deserves a fair trial.”

“We do not want anyone high-fiving tonight,” Sharpton said. “There is no victory here. There are no winners here. They lost their son. This is not about gloating. This is about pursuing justice.”

A crowd of nearly 200 people gathered at Allen Chapel A.M.E church in Sanford, the local hub for organizers surrounding the Martin cause.

“The mood is just … happy, but still more like a sigh of relief,” said Traymon Williams, 26, who joined his neighbors at the church after watching Corey’s news conference at home. “It feels just like when you have a headache, a migraine and you take an aspirin and you just can feel the pressure slowly starting to ease.”

But both the defense and prosecution face the challenge of trying a case that has drawn extraordinary media scrutiny, and inflamed passions both for and against Zimmerman. Jury selection will be a crucial and difficult task given the tremendous media coverage afforded to the shooting, experts said.

“This case is won or lost in jury selection,” Geragos said.

For some, the prosecution of Zimmerman may also be a symbolic test of Florida’s ability to conduct a fair trial in a case that has polarized the public and fueled marches and protests across the country. Just last year, Casey Anthony, a young Florida mother accused of killing her 2-year-old daughter, was acquitted of murder, a verdict that many decried as a miscarriage of justice.

“The state of Florida is on trial here,” said Kenneth Nunn. “A law professor at the University of Florida. “Not just Zimmerman.”