IT’S been 10 years since Florida enacted a beefed-up Stand Your Ground law. Since 2005, roughly half the states have passed this law, or one like it. The National Rifle Association led the charge, arguing that Stand Your Ground laws would improve public safety and protect honest citizens. Similar laws have existed elsewhere for over a century, but Florida’s law substantially altered the legal equation.

Under the new breed of laws, a person who has harmed or killed another in a public place can presumptively claim self-defense. The police must accept the claim’s validity. In other words, the individual need only assert the belief that the use of force was necessary to prevent serious harm or death. Coupled with that is special legal protection that makes the person (as the Florida law says) “immune from criminal prosecution and civil action.” Prosecution is still possible, but it is much more difficult.

A result, according to the Association of Prosecuting Attorneys, is hamstrung investigations and legal protections greater than those afforded to police officers. Not only have these laws failed to increase public safety, they have also turned the clock back to the mythologized mayhem of the Wild West.

The Tampa Bay Times examined the effects of Florida’s 2005 law in more than 200 cases (about half of them fatal) through mid-2012. It reported that the law’s chief beneficiaries were “those with records of crime and violence.” Nearly 60 percent of those making self-defense claims when a person was killed had been arrested at least once before; a third of those had been accused of violent crimes in the past; over a third had illegally carried guns in the past or had threatened others with them.