By Daniel Trotta and Barbara Liston
SANFORD, Florida (Reuters) - Six anonymous women began deliberating on Friday whether to convict George Zimmerman for the shooting death of unarmed black teenager Trayvon Martin in a case that has captivated and divided the U.S. public for the past 16 months.
After presiding over 12 days of testimony and two days of closing arguments, Seminole County Judge Debra Nelson turned the case over to a jury sequestered since the trial began last month. They broke for the day without reaching a verdict.
They will try to settle a case that has dominated U.S. media, sparked street demonstrations and raised questions about race and guns in America.
Jurors must reach a unanimous verdict on either second-degree murder, manslaughter or acquittal. A deadlocked jury would result in a mistrial, possibly leading to the whole courtroom drama unfolding once again.
Two hours into their meeting, which started at 2:30 p.m. (1830 GMT), they asked the judge for a full inventory of the evidence. They broke deliberations for the night at 6:00 p.m. Eastern time (2200 GMT) without issuing a verdict and will continue at 9:00 a.m. (1300 GMT) on Saturday.
The judge will allow them to set their own working hours
Zimmerman, 29, says he shot Martin in self-defense after he was attacked on the rainy night of February 26, 2012, in the central Florida town of Sanford. Prosecutors contend Zimmerman was a "wannabe cop" who tracked down the teenager and shot him without justification.
Zimmerman's family appealed for calm, whatever the verdict, saying they had complete trust in the U.S. justice system.
"As we await a verdict we will remain hopeful and ask for the public to remain peaceful no matter the outcome," they said in a statement to CNN. "The judicial system has run its course, pray for justice, pray for peace, pray for our country."
It all began when Zimmerman, the neighborhood watch coordinator, called police to report a suspicious person in his neighborhood. That turned out to be Martin, a guest in the home of his father's fiancée, who lived inside the gated community.
A fight ensued, and after Zimmerman suffered several head injuries, he shot Martin once through the heart with a Kel Tec 9 mm pistol fully loaded with hollow-point bullets.
In closing arguments on Friday, lead defense lawyer Mark O'Mara attempted to shift the blame to Martin, saying he was the aggressor who attacked Zimmerman after lying in wait.
To convict Zimmerman of second-degree murder, which could lead to a sentence of life in prison, the jury must find he acted with ill will, spite or hatred.
The hateful person that rainy night was Martin, not Zimmerman, O'Mara told the jury.
"The person who decided this was going to continue, was going to become a violent event, was the guy who didn't go home when he had a chance to. It was the guy who decided to lie in wait," O'Mara said.
The jury can also opt for manslaughter, which has a lesser burden of culpable negligence. That carries a prison sentence of up to 30 years.
Earlier, O'Mara warned jurors against filling in holes in the prosecution's case, cautioning against making presumptions and assumptions.
Yet he invited them to form their own conclusions about Martin, particularly in the four-minute gap that O'Mara said passed between Zimmerman's losing sight of Martin and when Martin attacked.
He dramatized that length of time by pausing for four minutes, leaving the courtroom silent.
"Four minutes. You get to figure out what Trayvon Martin was doing," O'Mara told the jury. "Four minutes to do what? To run home. To walk home."
Prosecutors had one final rebuttal, when John Guy told the jury, "The defendant didn't shoot Trayvon Martin because he had to. He shot him because he wanted to. That's the bottom line."
At the time of the encounter, Martin was on the phone with a friend from Miami who testified that she heard him ask, "What are you following me for?" Guy contended it was Martin who then feared for his safety.
When police initially declined to arrest Zimmerman, believing his account of self-defense, it provoked demonstrations, first in Sanford's black neighborhood of Goldsboro, where people accused Zimmerman of racial profiling and demanded his arrest.
Protests spread to small towns and big cities across the United States, prompting celebrity tweets, cable news shouting matches, and scrutiny of Florida's Stand Your Ground self-defense law, which police cited in letting Zimmerman to go free.
The case drew the attention of President Barack Obama, who said, "If I had a son, he'd look like Trayvon."
After the Sanford police chief stepped down the normally assigned prosecutor recused himself, the governor appointed a special prosecutor, who charged Zimmerman with second-degree murder 45 days after the shooting.
In Sanford, officials said on Friday they were prepared for a possible return of the impassioned demonstrations that arose last year but expected calm.
"We will not tolerate anyone who uses the verdict as an excuse to violate the law," Sheriff Donald Eslinger told reporters.
(Additional reporting by Kevin Gray in Miami; Writing by Daniel Trotta; Editing by Dina Kyriakidou, Bernard Orr)