George Zimmerman defence makes closing argument 12 July 2013 Last updated at 18:24 The defence has rested its case in the murder trial of a Florida neighbourhood watchman who shot dead an unarmed black teenager last year. Twenty-nine-year-old George Zimmerman's lawyer said they had proven his "pure, unadulterated innocence" in the killing of 17-year-old Trayvon Martin. But prosecutors said he had told a series of lies about the shooting. A jury of six women will now decide if he should be acquitted, or convicted of second-degree murder or manslaughter. They must decide who was at fault in the fatal confrontation on the night of 26 February 2012 as Martin walked from a shop to the home of his father's fiancee in a gated community in Sanford, Florida. Dramatic pause As the nation awaits the outcome, police and city leaders in southern Florida say they are ready for any mass protests or even civil unrest if Mr Zimmerman walks free. David Willis BBC News, Sanford Not far from the Magic Kingdom a spectacle almost as riveting as any Walt Disney himself could have put together is playing out. A six-woman jury stands ready to decide the outcome of a case that has divided not only this community but much of America. The shooting dead of an unarmed black teenager has brought to the fore issues which had previously been simmering beneath the surface - such as racial profiling, gun control and equal justice under the law for African Americans and Hispanics. Blanket coverage of the three-week trial on cable television in the US has only served to heighten the debate. Police and community leaders have appealed for calm in advance of the verdict, but if George Zimmerman is acquitted there's every chance of a repeat of the protests which preceded his arrest, and the concern that unlike last time such demonstrations may not be so peaceful. Defence lawyer Mark O'Mara told the sequestered jury on Friday that Mr Zimmerman's guilt had not been proven beyond reasonable doubt. He said the shooting was in self-defence. The prosecution's case was built on a series of "could've beens" and "maybes," he added. He said the defendant had shown no ill will, hate or spite during his encounter with Martin. Mr O'Mara also challenged the jury to think about what Martin was doing for four minutes - after a friend on the phone told him to start running, but before he came face to face with Mr Zimmerman. The defence lawyer fell silent for four minutes, and said the teenager had spent that amount of time planning his attack instead of returning home. Mr O'Mara said the aggressor was Martin, "the guy who decided not to go home when he had a chance to." Summing up, he used a slideshow, an animation of the fight, and cardboard cut-outs of Mr Zimmerman and Martin. 'Every child's nightmare' In rebuttal, prosecutor John Guy argued that Mr Zimmerman had repeatedly lied in his statements about the shooting. Isn't that every child's worst nightmare, to be followed on the way home in the dark by a stranger? Mr Guy said. Isn't that every child's worst fear? Mr Zimmerman's account of how he grabbed his gun from his holster at his waist as the teenager straddled him is physically impossible, the prosecutor said. "The defendant didn't shoot Trayvon Martin because he had to, he shot him because he wanted to," Mr Guy said. That's the bottom line. Judge Debra Nelson will next give the jurors their instructions before they retire to consider a verdict. They have heard 12 days of testimony by dozens of witnesses. Without explicitly discussing race, the prosecution has suggested Mr Zimmerman assumed the African-American teenager, who was wearing a hooded sweatshirt as he walked in the rain, was up to no good. But the defence says Martin punched their client, slammed his head into the pavement and reached for Mr Zimmerman's gun. The accused, who was legally armed with a pistol, had been sitting in his vehicle on a dark street when he saw Martin. The accused telephoned police to report a suspicious person, then left his vehicle in apparent pursuit of the teenager. Mr Zimmerman, who identifies himself as Hispanic, could face life in prison if convicted on the murder charge. Last year, the case prompted mass, peaceful protests across the US, with critics questioning why it took police six weeks to arrest Mr Zimmerman.