George Zimmerman will be charged today in Trayvon Martin's death

Florida special prosecutor Angela Corey is expected to charge — as early as today — neighborhood watch volunteer George Zimmerman in the shooting of Trayvon Martin, various media outlets, citing anonymous sources, are reporting.

Corey will make an announcement on the case at 6 p.m. Wednesday, her office confirmed.

The word came shortly after Trayvon's parents attended a national conference in Washington, D.C. led by Rev. Al Sharpton. They expressed fear that people will react to the news with violence and urged calm.

“We are imploring everybody to be peaceful,” family attorney Benjamin Crump said. “You can be resolute...but you've got to be peaceful."

Said Sharpton: "We do not condone or support, in any way, any violence."

It was not immediately clear what charge Zimmerman will face. A source briefed on the case told The Miami Herald that Zimmerman would face a single charge, something less than a first-degree felony.

A first-degree felony is the most serious felony, reserved for murder cases with 30-year sentences.

The prosecutor’s decision capped weeks of protests nationwide, which were marked by student walk-outs in South Florida and throngs of marchers wearing hoodies in cities from New York to Seattle. The case of a hooded high school junior who went for a walk in the rain to get snacks became a national symbol of racial injustice. And for others, it became a glaring example of the media’s rush to judgment and willingness to try a case in the newsroom instead of a courtroom.

Trayvon Martin died Feb. 26 after he returned from 7-Eleven, where he bought Skittles and iced tea. While walking back from the store to the townhouse he was visiting at the Retreat at Twin Lakes, the gated community’s watch captain spotted him and found him suspicious. There had been recent burglaries, Trayvon was walking slow, “looking about,” and appeared to be on drugs, Zimmerman told a police operator.

Zimmerman, a married man who worked in the mortgage and insurance industries while studying criminal justice, had called police to report a variety of crimes 46 times in eight years. In the past year, he had reported black men looking “suspicious” on four prior occasions.

The watch captain’s four-minute call that night would be played hundreds of times on national media and scrutinized to its finest detail on social networking sites. In it, Zimmerman was heard huffing and puffing as he got out of his truck to tail Trayvon and figure out where he went, because the teen took off running.

The operator told him not to follow him, and Zimmerman muttered profanities lamenting how the bad guys “always get away.”

Zimmerman later told police that after the operator told him not to follow Trayvon, he headed back to his truck, and that’s when the teenager came up from behind him. The two exchanged words and Trayvon allegedly punched Zimmerman in the face, breaking his nose, Zimmerman’s attorneys and family have said.

A scuffle ensued, and Zimmerman reached for his licensed Kel Tek 9 mm semiautomatic handgun from the holster on his waist and fired once, hitting Travyon in the chest.

Trayvon's mother, Sybrina, called the past 45 days "a nightmare."

"This is coming from a mother's perspective. I have been up and down, as if I'm on a roller coaster," she said. "But I know, beyond a shadow of a doubt, that justice will be served."

She said she was concerned when Zimmerman's legal team said Tuesday that they didn't know their client's whereabouts. "But we do have faith in the justice system that they will find him when it's time, or when they are ready to arrest him," she said.

The Sanford Police Department immediately came under fire for its handling of the investigation, as witnesses said detectives performed cursory interviews to support the set of facts they were accepting as true: that Zimmerman had committed a justifiable homicide.

The accounts from witnesses were mixed, although they largely agreed that they all assumed that a person they heard screaming for help was now dead. Zimmerman claimed those cries were his unanswered calls for help, and Sanford police believed him.

“I think this is unprecedented in Florida,” said Derek Brett, a Central Florida attorney who represents one of the witnesses, whose name has not been made public. “I am not saying it’s not nice for police and the State Attorney’s Office to do their due diligence, but in 99.9 cases out of 100, there would have been an arrest. You have a dead body and a guy saying, ‘I shot him.’ That’s your probable cause.”

Sanford Police Chief Bill Lee said he did not make an arrest, because there was no probable cause to refute Zimmerman’s story – and Florida’s controversial “Stand Your Ground” law made him immune from arrest.

The law eliminates a citizen’s duty to retreat when faced with the reasonable fear of death or great bodily harm. The law says someone who starts a fight should exhaust all other means before resorting to deadly force.

The controversy that exploded after the shooting has put the future of the hotly debated law in doubt.

Lee’s future is murky as well: After the Sanford city commission took a “no confidence” vote against the embattled chief, Lee took a paid leave of absence.

It was later revealed that the police senior investigator in the case had requested criminal charges be filed early on in the investigation, but the Brevard-Seminole County State Attorney held off pending further review.

The case was transferred to special prosecutor Corey, based in Jacksonville, and is now being investigated by the FBI, Florida Department of Law Enforcement and the Department of Justice Civil Rights division.

Corey opted against using a grand jury to decide whether to file charges.

Zimmerman’s case was further complicated when the city of Sanford released surveillance video of him arriving at the police station. A professionally enhanced version shows a cut on his head, but the grainy video posted on the city’s website showed Zimmerman had no trouble walking and did not have any blood on his clothes.

In television interviews last week, his former attorney, Hal Uhrig, stressed that a person can be killed even without bloodshed. He noted “shaken baby syndrome,” and the death of actress Natasha Richardson, who died after a single blow to the head during a skiing accident.