The tragic killing of Florida teenager Trayvon Martin has put a spotlight on the state's open-ended Stand Your Ground law, which allows people to defend themselves with deadly force as long as they reasonably believe it is necessary to protect themselves.

The shooting death of Martin, a 17-year-old high school student, at the hands of an armed, self-appointed crime watch volunteer has focused public attention on the contentious law. George Zimmerman, the man who pulled the trigger, claims he was acting in self-defense when he forced to kill the unarmed teenager. Recent developments -- including the release of a phone call Martin made to friend only minutes before his death -- make it clear the teenager did not pose a violent threat to Zimmerman, calling attention to a law that clears a suspect from prosecution if the state does not find evidence to dispute their claim of self-defense.

1. Policy Is An Expansion Of Law Authorizing Justifiable Use Of Force in Home

Florida essentially became a shoot first state in 2005, when former Gov. Jeb Bush signed the legislation into law. At the time Bush said he supported the measure because when faced with a serious threat to one's life, to have to retreat and put yourself in a very precarious position defies common sense.

The law extends what has been called the Castle Doctrine, which asserts that a person has the right to defend his or her home with deadly force if they are in fear of great bodily injury. Unlike similar laws across the country, the Florida provision does not require residents to retreat before using lethal force -- whether it be with a gun, knife or baseball bat -- against a home intruder, a concept that is based off the English common-law idea that an individual's home is their castle.

With the Stand Your Ground law, a person no longer needs to prove that they feared for their safety, only that the individual they either injured or killed -- even those who are unarmed -- had forcefully and unlawfully intruded. Unlike the initial Castle Doctrine, the newer law extends the principle to vehicles and public places and also does away with an earlier requirement that said a person attacked in a public place must retreat if it is a viable option.

Now, that same person, in the law's words, has no duty to retreat and has the right to stand his or her ground and meet force with force, including deadly force. Plus, it is now forbidden to arrest, detain or prosecute an individual deemed to be protected by the policy.

2. Justifiable Homicide Rates Have Tripled Since Passage

Florida averaged 12 deaths by justifiable homicide in the four years -- 2000 to 2004 -- preceding the passage of Stand Your Ground, according to the Florida Department of Law Enforcement. Afterwards, the number of justifiable deaths almost tripled to an average of 35 per year between 2005 and 2010.

The Legislature needs to take a look at Stand Your Ground, Florida Sen. Oscar Braynon, D-Miami Gardens, recently told The Miami Herald. This is a perfect case of where it goes awry. This could only be the beginning of more problems down the road. It has unintended consequences.

The self-defense law has been invoked in at least 93 cases involving 65 deaths, according to a review from the St. Petersburg Times, which added that in a majority of cases the defendant's use of force was excused by prosecutors and the courts.

For his part, Gov. Rick Scott has not gone as far as denouncing the law, although he told reporters that that he's hopeful that the Legislature would be interested in taking that up if there is something about the law that should be altered or discussed.

While Florida currently imposes a three-day waiting period on handgun purchases and inflicts liability on individuals who make their firearms accessible to children, the state still has relatively loose gun control regulations. For instance, Florida does not require firearm dealers to obtain state licenses, does not mandate firearm registration, does not limit the number of guns that may be purchased at one point, and does not regulate the sale of assault weapons, 50 caliber rifles or large capacities of ammunition magazines, according to the Legal Community Against Violence.

3. Law Enforcement Officials Opposed Stand Your Ground

Prosecutors across the state opposed Stand Your Ground before it was enacted in October 2005, arguing that it allows people to use deadly force when it should not be used, usually without consequence.

In the aftermath of its passage, the Orlando Sentinel reports that some Orlando-area police agencies stopped investigating shootings involving self-defense claims, instead referring them directly to state prosecutors since they usually did not have grounds to arrest individuals who could be protected under Stand Your Ground.

Before the law took effect, former Miami Police Chief John Timoney made an ominous prediction about its potential consequences.

Whether it's trick-or-treaters or kids playing in the yard of someone who doesn't want them there or some drunk guy stumbling into the wrong house you're encouraging people to possibly use deadly physical force where it shouldn't be used, Timoney told The New York Times.

4. Several States Have Adopted Similar, NRA-Advocated, Laws

At least 16 states have adopted similar legislation following the passage of Florida's Stand Your Ground, mostly centered in Southern and Midwestern regions, putting the total number of state's with the policy at 23. The law has been heavily advocated by the National Rifle Association, which lobbied extensively for its passage, at one point saying it put the law on the side of law-abiding citizens.

In 2010, when the law had already resulted in some high-profile deaths and injuries, the NRA's Florida lobbyist Marion Hammer told the Tampa Bay Times the measure is needed to protect lawful citizens from unwarranted arrests, arguing it simply gives people the right to protect themselves.

In a statement responding to the Trayvon Martin's death, Brady Campaign to Prevent Gun Violence President Dan Gross said the tragedy is representative of the NRA's vision for America.

The NRA wants us to be a nation without any gun laws, a nation where just about anybody can get a gun and take it anywhere, Gross said. Their leaders and spokespeople use fear, paranoia and misleading notions of self-defense to justify flooding our streets with armed and violent people, and the result is more tragedies like Trayvon's.

5. No Federal Law on Record Restricts the Policy

Although there are a handful of federal gun control laws on the books, there currently is no national law that strictly forbids the self-defense justification of Stand Your Ground.

In fact, there is no federal law generally prohibiting the carrying of firearms by U.S. citizens for protection or other lawful purposes, aside from the limited exceptions outlined in the Federal Gun-Free School Zones Act of 1990. Only two regions -- Illinois and Washington, D.C -- prohibit individuals from carrying guns on their person. However, the open carrying of firearms without a licensing requirement is legal in 31 states, although some of those states require licenses for the carrying of concealed weapons.