(CBS/AP) SANFORD, Fla. - Prosecutors face steep hurdles to win a second-degree murder conviction against neighborhood watch volunteer George Zimmerman in the shooting death of unarmed teenager Trayvon Martin, experts say.
Zimmerman was charged after a public campaign to make an arrest in the shooting that galvanized the nation for weeks. Now the prosecutor and her team will have to prove Zimmerman intentionally went after Martin instead of shooting him in self-defense, to refute arguments that a Florida law empowered him to use deadly force.
Zimmerman, 28, who turned himself in at a county jail Wednesday after prosecutor Angela Corey announced the charge, was to appear before a magistrate Thursday and plead not guilty in the Feb. 26 shooting of the 17-year-old that set off a nationwide debate about racial profiling and the rights to self-defense.
"He's frustrated. He's tired. He's stressed. So, we just need to sort of take it one day at a time," O'Mara told co-hosts Erica Hill, Gayle King and Charlie Rose.
On Wednesday, O'Mara said Zimmerman was concerned about getting a fair trial.
"He is a client who has a lot of hatred focused on him. I'm hoping the hatred settles down ... he has the right to his own safety and the case being tried before a judge and jury," O'Mara said.
Trayvon Martin's parents, Sybrina Fulton and Tracy Martin, said on "CBS This Morning" that they were "at ease," "excited" and "overwhelmed" by Zimmerman's arrest.
However, Fulton, who has campaigned with the rest of the family for an arrest and prosecution, said she thought the shooting was an accident.
Asked on NBC's "Today" what she would say to Zimmerman face-to-face, Fulton said she wanted an apology, then added: "I believe it was an accident. I believe that it just got out of control and he couldn't turn the clock back." She did not say more about how she thinks the shooting happened.
Legal experts said Corey chose a tough route with the murder charge, which could send Zimmerman to prison for life if he's convicted, over manslaughter, which usually carries 15-year prison terms and covers reckless or negligent killings.
The prosecutors must prove Zimmerman's shooting of Martin was rooted in hatred or ill will and counter his claims that he shot Martin to protect himself while patrolling his gated community in the Orlando suburb of Sanford. Zimmerman's lawyers would only have to prove by a preponderance of evidence a relatively low legal standard that he acted in self-defense at a pretrial hearing to prevent the case from going to trial.
There's a "high likelihood it could be dismissed by the judge even before the jury gets to hear the case," Florida defense attorney Richard Hornsby said.
Corey announced the charges Wednesday after an extraordinary 45-day campaign for Zimmerman's arrest, led by Martin's parents and civil rights activists, including the Rev. Al Sharpton and the Rev. Jesse Jackson. Protesters wore hooded sweatshirts like the one Martin had on the night of the shooting. The debate reached all the way to the White House, where President Barack Obama observed last month: "If I had a son, he'd look like Trayvon."
Corey would not discuss how she reconciled conflicting accounts of the shooting by Zimmerman, witnesses and phone recordings that indicated Martin thought Zimmerman was following him.
"We do not prosecute by public pressure or by petition. We prosecute based on the facts on any given case as well as the laws of the state of Florida," Corey said.
Many attorneys said they had expected the prosecutor to opt for the lesser charge of manslaughter. The most severe homicide charge, first-degree murder, is subject to the death penalty in Florida and requires premeditation something all sides agreed was not present in this case.
"I predicted manslaughter, so I'm a little surprised," said Michael Seigel, a former federal prosecutor who now teaches law at the University of Florida. "But she has more facts than I do."
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.