(CNN) — In the months after the Florida Legislature passed a law in 2005 allowing residents to use deadly force to protect themselves no matter where they were, gun-control advocates plastered the state with fliers bearing warnings to tourists.

Be careful, the fliers said. Florida had become a “shoot first” state.

The issue has remained in the news, on and off, ever since, but perhaps never so much as now in the aftermath of the shooting death of an unarmed teen in Sanford, Florida.

A neighborhood watch volunteer, George Zimmerman, has claimed self-defense in the February 26 shooting of 17-year-old Trayvon Martin, who was killed while walking back to the house of his father’s fiancee after a trip to a convenience store.

Lawyer: Phone records cut self-defense claim

Florida’s “stand your ground” law appears to be central to the case.

The law allows people to use deadly force away from their homes — where such force has long been allowed — if they have reasonable fear an assailant could seriously harm them or someone else.

It also eliminates a longstanding “duty to retreat” in the face of imminent harm, asserting that would-be crime victims have the right to “stand their ground” and “meet force with force” when attacked as long as they are in a place they have a right to be, are not engaged in unlawful activity and believe that their life and safety was in danger.

It won with the strong endorsement of the National Rifle Association, or NRA, which at the time said it put the law “on the side of law-abiding citizens.”

Justice Department, FBI to probe Florida teen’s death

Since its enactment, it has been frequently cited in cases ranging from a 2006 incident in which a man sprayed a vehicle carrying a known gang member with 14 bullets to the 2011 case of a man who was cleared under “stand your ground” after stabbing a man in the head with an ice pick during a road rage incident, according to legal and media accounts.

The number of justifiable homicides reported in the state has skyrocketed since the law went into effect.

In the five years before the law’s approval, Florida averaged 12 justifiable homicides a year, according to the Florida Department of Law Enforcement. In the six years since, the average is 33.

“This is the NRA’s vision of America: People carrying loaded guns on the street, shooting first and asking questions later,” said Daniel Vice, senior attorney for the Brady Campaign to Prevent Gun Violence.

The NRA did not immediately respond to a telephone message left with its public affairs office seeking comment.

In 2005, the bill’s chief NRA lobbyist, Marion Hammer, told CNN that having to retreat in the face of danger “defies common sense.”

“The law is constructed to give law-abiding people the right to protect themselves when they are attacked,” she said at the time. “I think the message to criminals is going to be — you break into a home, you run the risk of being shot. You attack people on the street, you run the risk of being shot.”

Vice said the issue isn’t self-defense. “The question is whether you can provoke confrontation and then shoot to kill,” Vice said.

That’s precisely what Trayvon’s father, Stacy Martin, says he believes Zimmerman did when he followed the teenager as he walked, then ran, down the street in the gated community where he was staying.

911 calls paint picture of chaos

The family’s attorney, Benjamin Crump, calls the self-defense claim preposterous.

“You can’t go pick a fight with somebody and then say, ‘Oh, self-defense,’ when I shoot you,” he said.

Laws extending the traditional “castle doctrine” are in effect in 32 states, according to the Association of Prosecuting Attorneys, which counts as members about 1,000 prosecutors, many of them in larger jurisdictions.

The group opposes such laws, saying they don’t solve problems and tie the hands of prosecutors, said association President David LaBahn.

Opinion: My son could be Trayvon

“In its most egregious forms, it appears to be giving criminal immunity,” he said.

CNN legal analyst Jeffrey Toobin said the Florida law is particularly notable.

“I think the law is basically an invitation to use deadly force under basically any circumstance,” he told CNN’s “Anderson Cooper 360” on Monday.

HLN legal analyst Sunny Hostin said that, while Florida’s is perhaps the broadest such law in the country, she disagrees with assertions that it allows people who start confrontations to get away with murder.

“If you’re the first aggressor, if you are pursuing, you cannot avail yourself of this self-defense claim,” she said.

Florida Rep. Dennis Baxley, who was the prime House sponsor of the legislation, also weighed in on such a position.

“Nothing in ‘stand your ground’ authorizes (you) to pursue and confront,” he said.

The Ocala-Marion County lawmaker said the Sanford incident is not a reflection on the law.

“The anti-gun faction blames the law for certain problems,” Baxley said. “It’s been good public policy since 2005. We have seen a decrease in violent crime.” He did not provide statistics.

Gov. Rick Scott told reporters on Tuesday that, once the Sanford case is investigated, the law may need review.

“When you see any violence, it is always positive to go back and think about existing laws,” Scott said. “To review the impact and its consequences. ”