College student Jajuan Kelley covers his mouth with a Skittles wrapper as he rallies against

One year after 17-year-old Trayvon Martin was shot and killed by an armed neighborhood watchman, setting off a national debate about race and gun laws, the campaign to change state self-defense laws in Martin's name has petered out.

George Zimmerman, the neighborhood watch volunteer facing second-degree murder charges, said he shot Martin in self-defense last Feb. 26 after he decided to follow him in the Sanford, Fla., gated community because Martin looked suspicious. Zimmerman called the police and then approached Martin, and they ended up in a physical fight. Zimmerman, saying he feared for his life, then shot Martin. He was not charged with a crime for several weeks, and his defense attorneys argue he's immune from prosecution under Florida's "stand your ground" law.

The incident led immediately to scrutiny of the law, which is on the books of 20 states in various forms. Basically, "stand your ground" says that people can use lethal force against an attacker without first attempting to retreat if they have reason to fear for their lives. Most states already allowed people to defend themselves in this way if they're attacked at home, but "stand your ground" went a step further to cover all public places.

A Tampa Bay Times analysis of 200 "stand your ground" cases in Florida—the law was adopted there in 2005—found that the law has been inconsistently applied, with one man escaping homicide prosecution even though he left an altercation to get his gun from his car, returned and then shot the attacker.

After the Martin shooting and subsequent uproar, a coalition of civil rights groups and New York City Mayor Michael Bloomberg, the nation's highest-profile gun-control advocate, started a campaign, called "Second Chance on Shoot First," to encourage the repeal of these laws. Soon after, Florida Gov. Rick Scott, a Republican, appointed a task force to study the law. Meanwhile, lawmakers in at least four states with "stand your ground" laws introduced legislation to alter or repeal their laws.

But not much has happened since then on the state level. On Friday, the Florida task force released its final recommendations on the law, concluding that it works and should not be repealed. (The task force did recommend that prosecutors and law enforcement officers should receive increased training on the law to make sure it is applied consistently.)

In addition, none of the bills to repeal or change "stand your ground" in other states passed.