A year after Trayvon Martin shooting, is America much changed?

The trend in the states toward liberalized self-defense and gun laws appears to have stalled in the year since unarmed teenager Trayvon Martin was shot and killed in Sanford, Fla. But states that already had such laws have stuck with them.

A year ago Trayvon Martin made a fateful decision: to take a break from the NBA all-star game on TV and kick down to the corner convenience mart, where he bought a Snapple and a bag of Skittles.

The lanky 17-year-old never returned to the home where his dad was staying in Sanford, Fla. An armed neighborhood watchman had targeted Trayvon as suspicious as he walked back from the store that evening, confronted him, and, after a tussle, killed him with a close-range gunshot to the chest. It wasn't until the next morning that Trayvon's father, Tracy Martin, learned what had happened to his missing son.

The death of Trayvon, an African-American, became major national news after Sanford police declined to charge his shooter, citing Florida's self-defense laws, and the teenager's disbelieving parents began lobbying for justice. It would spur, in the year that followed, a state reversal of the Sanford police decision not to arrest the shooter, a closer look at liberalized gun laws, and a hiatus on new state laws sanctioning lethal force to perceived threats.  

"For years when permissive gun laws were being enacted, gun control advocates said, 'This will lead to people shooting people for no reason,' and, the truth is, studies do not back up that argument," says Adam Winkler, a constitutional law professor at the University of California, Los Angeles, Law School. "But what we suddenly had was a big, high-profile incident that seemed to suggest that's what happened – that people roaming around with guns are a danger to everybody, including an innocent kid walking around with Skittles."

George Zimmerman, 27, now faces trial for second-degree murder – and his defense team is expected to argue during a pretrial hearing in April that he acted in accord with Florida's Stand Your Ground law and was within his rights to defend himself with deadly force, even though he forced a confrontation with Trayvon. 

"My hope is that we've sort of moved past the initial emotional reaction to more thoughtful reflection on what this means for the country, to have laws that make it so easy for disputes that could otherwise be resolved peacefully to lead to deadly outcomes that we don't seem to condemn," say Joelle Moreno, a law professor at Florida International University.

Starting in 2005, at least 24 states have enacted versions of so-called Stand Your Ground laws, but no additional states passed such a law since Trayvon's death. Others point to the attention the case brought to a driver of those laws, the American Legislative Exchange Council, which has since shifted its focus to fiscal policy instead of gun policy.

Travyon's parents, Tracy Martin and Sabrina Fulton, will attend a candlelight vigil in New York City Tuesday evening at 7:15, the time that their son died a year ago. With the help of their lawyer, Ben Crump, they have pushed to keep Trayvon's death at the forefront of policy discussions and formed a lobbying group urging the 24 states with some form of Stand your Ground laws to reassess the statutes' effectiveness.

"We [want to] make sure that no other parents have to go through what we have gone through in the last year," Ms. Fulton told CNN's Piers Morgan on Monday night.

The Trayvon Martin case has been compared with the 1955 lynching of 14-year-old Emmett Till, an event that sparked the civil rights movement, and it sparked numerous pro-Trayvon rallies across the country, where many protesters wore hoodies like the one Trayvon had on when he caught Mr. Zimmerman's attention.

"[W]ithout all of that collective action, Zimmerman would be walking around free and would have never seen the inside of a courtroom," writes CNN columnist Roland Martin on Tuesday. "Stand-your-ground laws would exist with nary a peep of opposition; and we would all be living our lives as if all is good."

Nevertheless, a Stand Your Ground Commission that convened in Florida after Trayvon's death found no cause to repeal or substantially change the law. But state Rep. Alan Williams has introduced a bill that would do just that. Police organizations and prosecutor groups have also panned such laws, saying they minimize and marginalize prosecutorial discretion to seek justice.

The case has also energized gun rights proponents and some conservatives, many of whom have made contributions to Zimmerman's defense fund and painted Trayvon in a less-than-favorable light. They have also alleged that the media shaped a false narrative that Trayvon's race played a role in the shooting, noting that Zimmerman himself has black and Hispanic ancestry. In some cases the critics were right: NBC News has apologized for manipulating audio recordings of Zimmerman's 911 call to police that made him sound racist.

Trayvon's death foreshadowed what became a year of deadly shootings, including massacres at an Aurora, Colo., movie theater and an elementary school in Newtown, Conn. The result has been an unprecedented push by President Obama and Democrats in Washington and across the country to curb the longtime trend toward laxer gun laws. Some scholars say that Trayvon's death – and the public reaction to an apparent miscarriage of justice – is what set off the debate, now growing louder, about the expansion of gun rights in the past decade.

"Before the Trayvon Martin shooting, the issue was, are we going to allow guns in bars and on college campuses and in churches, and that's slowed, even stalled, after the shooting," says Adam Winkler, a constitutional law professor at the University of California, Los Angeles, Law School. "And after Aurora and Newtown, we seem to have reversed course in a way that was not even conceivable before."

What happened to Trayvon "caused Americans to start thinking about the whole gun culture, guns in our society … and rights around when we can carry and who should carry," says Larry Davis, a race scholar at the University of Pittsburgh.