New York // Florida's controversial self-defence law has emerged at the centre of a furious national debate over the shooting of Trayvon Martin, an unarmed black teenager, and whether his confessed killer can be charged under the law.
The 'Stand Your Ground' law, as it is commonly known, was passed by the Florida legislature in 2005, the first state out of 22 that have enacted similar laws.
Under traditional law, deadly force is only allowed by an individual if the option to retreat from a violent situation proves to be impossible. With 'Stand Your Ground', deadly force can be used if someone believes they are in danger of being killed or injured.
The law tips the benefit of the doubt heavily in favour of people claiming self defence - especially in cases when the only other witness is dead.
And this was what was behind the decision by the police department in Sanford, Florida not to press charges in the killing of 17-year-old Martin.
He was killed a month ago by George Zimmerman, 28, an armed neighbourhood watch volunteer who claims he shot in self defence when Martin attacked him.
Growing evidence, however, has contradicted Mr Zimmerman's story and sparked nationwide protests via social media this week.
The protests have led to the temporary resignation of Sanford's police chief, a civil rights investigation by the federal Justice Department, and a Florida grand jury prepared to decide whether murder charges should be laid.
Even Barack Obama, the US president, weighed in on Friday, saying that: "My main message is to the parents of Trayvon Martin. If I had a son, he'd look like Trayvon. And I think they are right to expect that all of us as Americans are going to take this with the seriousness it deserves, and that we're going to get to the bottom of exactly what happened."
Mr Zimmerman, who had made 46 calls to 911 in a little over a year to report suspicious people, was recorded telling a police dispatcher that he was following a black male he had suspected of casing houses. In the call, he referred to Martin with a racial slur. At the time, Martin was walking from a convenience store, holding a can of ice tea and a packet of Skittles, to his father's fiancee's house in the rain, and was wearing a hooded sweatshirt.
In Mr Zimmerman's account to the police, he said that he approached Martin and then was attacked from behind as he tried to get back into his SUV and that he shot in self defence. But evidence appears to show that he was the aggressor. In the 911 call the dispatcher tells Mr Zimmerman not to approach Martin, an order he ignores. According to Martin's girlfriend, who was on the phone with him until the altercation, Martin told her he was being followed by a man in a truck and that he was going to walk away fast.
In 911 calls from neighbours, a pleading high-pitched voice can be heard before two gunshots silence it. Mr Zimmerman claims the voice is his, but Martin's parents as well as witnesses say that the voice is clearly Martin's.
The authors of the law in Florida have said that it simply "empowers" people to protect themselves, while critics - including local law enforcement officials - claim that it provides legal cover for vigilante justice, as well as what could be considered manslaughter or murder.
"We opposed it during time they implemented it and we've been living with it since," said Mr William Meggs, the state attorney in Tallahassee. Florida. "It was a totally unnecessary law."
Prosecutors have said 'Stand Your Ground' has been invoked with increasing regularity since 2005. In 2010, the Tampa Bay Times reported that in the first half of the decade there were an average of 34 justifiable homicides per year. By 2009, the average had spiked to 100.
"People who are using this law are not law-abiding citizens, they are gangs, thugs, drug dealers," said Mr Meggs.
He described how, in 2008, a daytime shoot-out by gang members killed a 15-year-old bystander. The two men charged with the murder had their cases thrown out.
"What this means, as illustrated by this case, is that two individuals, or even groups, can square off in the middle of a public street, exchange gunfire, and both be absolved from criminal liability if they were reasonably acting in self-defence," wrote Judge Terry Lewis at the time.
Mr Meggs said that law has been invoked in cases, especially domestic violence cases, he considers to be justified, but he thinks that they would have been covered by pre-Stand Your Ground self-defence laws anyway.
Prosecutors and legal scholars claim the law makes it too easy to claim self defence. Before trials even begin, judges can be asked by the defence to dismiss the case under 'Stand Your Ground' and that the required standard of evidence required is much less than that needed by juries. Often, with only one side of the story, judges are forced to dismiss the case.
"It's a much lower standard," added Zachary Weaver, a Florida attorney who wrote an extensive study of the law for the University of Miami Law Review in 2009. "And it becomes a large factor because less cases are prosecuted."
William Eddins, the state attorney in Pensacola, Florida, said many of his colleagues believed the widely publicised law, even before the Martin killing, contributes to the increasing violence as people know they have an option not to retreat in confrontations.
"We don't want laws sending the message that it's normal conduct to shoot someone in a road rage incident," said Garrett Epps, a scholar of constitutional law and civil rights at the University of Baltimore law school.
"This is a mainstreaming of violent behaviour that ought to trouble us all.
"Either we can go and be Mad Max or, if we want to live in a society where people resort to violence as little as possible, this law is something that ought be looked at."
Mr Meggs said he hopes that Martin's killing instigates a review of the law in Florida.
"We've been saying for years that its going to take the wrong person to get killed to bring attention to this law," said Mr Meggs. "And that's what happened."