(CNN) -- The six jurors contemplating George Zimmerman's future deliberated straight through lunch Saturday.
That fact alone doesn't reveal anything about the content of the discussions, of course, but it could -- maybe -- hint at a sense of urgency in the second day of deliberations.
There were 1,009 killings by firearm in Florida in 2012, but the one that took Trayvon Martin's life gripped the nation.
Various threads spun together to capture the public imagination. They include an adult firing upon an unarmed teen, claims of self-defense and accusations of racial profiling: Martin was black; Zimmerman, the son of a Peruvian mother and a white American father, identifies as Hispanic.
The February 26, 2012, shooting in Sanford, Florida, stirred debates about race in America and gun laws.
Zimmerman faces acquittal, conviction or the possibility of a hung jury if the six-person, all-woman jury cannot agree on a verdict.
Jurors had deliberated for 10 hours as of about 3:30 p.m. Saturday.
The jury got the case Friday afternoon after two weeks of testimony and dramatic closing arguments. A unanimous decision is required for conviction or acquittal.
Judge Debra Nelson on Friday read 27 pages of instructions outlining the jury's three options: convict Zimmerman of second-degree murder or of manslaughter, or find him not guilty. She approved the manslaughter option Thursday over the defense's vehement objection.
"All of us are depending on you to make a wise and legal decision," Nelson told the jurors.
Regardless of the outcome, the verdict will reverberate nationwide.
Some feel passionately that Zimmerman did nothing wrong and killed Martin in self-defense. Others accuse Zimmerman of profiling the unarmed 17-year-old, ignoring a 911 dispatcher's request not to follow him and killing him without justification.
The fateful day
Martin was walking back to his father's fiancee's house from a Sanford convenience store where he'd bought snacks.
Zimmerman, a neighborhood watch volunteer, spotted him and called police. The two got into an altercation that ended with Martin dead and panicked neighbors calling 911 to report anguished cries for help.
The now-29-year-old Zimmerman never denied shooting Martin. The question is why.
And who was crying for help that night, Martin or Zimmerman?
Zimmerman was 'wannabe police officer'
Nelson told the jurors that the prosecution has to prove beyond a reasonable doubt that Zimmerman is guilty.
"Your memory should be your asset," she told the jurors -- among other pieces of advice.
"It is up to you decide which evidence is reliable," Nelson said. "You should use your common sense."
Before jurors began their deliberations, attorneys made their case.
Assistant State Attorney Bernie de la Rionda characterized Zimmerman as untrustworthy. He picked apart interviews Zimmerman gave to police and the media.
Why would a scared man get out of his car and walk around after being told by a 911 dispatcher not to follow the victim, the prosecutor asked in his closing argument. Did Zimmerman walk toward Martin, or did Martin come after him? Should Zimmerman have had more than a bloody nose and scratches on his head if he'd had his head slammed on the ground by the victim?
The prosecution got one last chance to present its case Friday, when Assistant State Attorney John Guy rebutted the defense's closing argument.
Guy characterized Zimmerman as a frustrated wannabe police officer who took the law into his own hands. He had decided Martin was one of the criminals who had been victimizing his neighborhood, he said, then trailed him against the advice of police dispatchers.
"The defendant didn't shoot Trayvon Martin because he had to," Guy said. "He shot him because he wanted to. That's the bottom line."
Zimmerman, the prosecution said, had a powerful determination not to allow someone he had already decided was a criminal to escape.
"What is that when a grown man, frustrated, angry, with hate in his heart, gets out of his car with a loaded gun and follows a child? A stranger? In the dark? And shoots him through his heart? What is that?" Guy asked.
It was nothing but self-defense, defense attorney Mark O'Mara argued.
'Many coulda beens,' defense says
"How many 'coulda beens' have you heard from the state in this case?" O'Mara asked Friday. "How many 'what ifs' have you heard from the state in this case? They don't get to ask you that. No, no, no.
"Do not give anybody the benefit of the doubt except for George Zimmerman," the lawyer said.
O'Mara tried to discredit the prosecution's portrayal of Zimmerman as frustrated, spiteful and seeking vengeance.
His client wasn't the aggressor, the defense argued.
It was Martin who stalked Zimmerman and emerged from the darkness to pounce, the defense said. The teenager pinned Zimmerman to the ground and slammed his head into the sidewalk, according to O'Mara.
"That was somebody who used the availability of dangerous items, from his fist to the concrete, to cause great bodily injury against George Zimmerman," he said.
Guy ridiculed the argument that Zimmerman had suffered substantial injuries.
Repeated blows against concrete would have caused more damage than the rivulets of blood and bumps seen in photographs from the night of the shooting, he said.
Authorities brace for reaction to verdicts
While this drama played out in a Sanford courtroom, Florida authorities braced for the outcome.
In the weeks after Martin's death, tens of thousands attended rallies demanding Zimmerman's arrest and castigating authorities for their handling of the case. Some of them wore hoodies, as did Martin the night he was killed, in support of his family.
A lawyer for the late teenager's family said that while he wouldn't call Zimmerman a racist, "this case in its totality has a racial undertone to it."
Daryl Parks told CNN's Anderson Cooper that the defendant surmised Martin was a criminal like those who'd struck in his neighborhood before -- at least one of whom was black.
"The problem, in this case ... is that Trayvon was not one of those people," Parks said.
The defense has strongly rejected accusations that Zimmerman is racist. O'Mara cited his client's work as a mentor to black children and his taking a black girl to his prom as evidence of his non-racist beliefs.
His defenders have been passionate as well, especially about a person's right to defend himself with a gun when attacked. Debate swirled over Florida's "stand your ground" law, which allows those who believe they are in imminent danger to use deadly force to protect themselves.
Calls for peace
Zimmerman's family is urging people to accept the verdict, whatever it is.
"Though we maintain George committed no crime whatsoever, we acknowledge that the people who called for George's arrest and subsequent trial have now witnessed both events come to pass," the family said. "We hope now that as Americans we will all respect the rule of law, which begins with respecting the verdict. The judicial system has run its course -- pray for justice, pray for peace, pray for our country."
Authorities appealed for calm as well and took steps in case some did not heed those appeals.
The sheriff's office in Broward County, in the Miami area, said it had made a contingency plan to respond to incidents tied to a verdict.
"Freedom of expression is a constitutional right," the sheriff's office said. "While raising your voice is encouraged, using your hands is not."
Civil rights leader the Rev. Jesse Jackson Jr. was among those who appealed for peace.
"If Zimmerman is convicted, there should not be inappropriate celebrations, because a young man lost his life, and if he is not convicted, we should avoid violence, because it will only lead to more tragedies," Jackson said.
But O'Mara said that whatever the outcome, his client will not feel safe.
"There are a percentage of the population who are angry, they're upset, and they may well take it out on him," he said.