The controversially concluded Florida murder trial of George Zimmerman has prompted fresh debate over whether "stand your ground" self-defense laws hinder violence or, perversely, propel it.
The evidence appears mixed.
Some studies show enhanced public safety. Others suggest the opposite. One study concluded that several dozen men a month are killed as a consequence of the laws. In a speech this week, U.S. Attorney General Eric Holder showed himself to be among the skeptics.
The resulting ambiguity, like the Zimmerman trial itself, in which he was found not guilty of murdering 17-year-old Trayvon Martin, may confound anyone hoping for a neutral finding of fact. It also allows advocates and critics alike to cherry-pick their preferred experts, which can enliven debate but complicate lawmaking.
"It's good that whatever perspective you take is based on data, and not just anecdotes," Miami-based attorney Leigh-Ann Buchanan said in an interview Wednesday.
Buchanan is a co-chair of an American Bar Association task force that's studying stand-your-ground laws. The task force has held three hearings so far and it plans another next month in San Francisco. The group will report next year on various questions surrounding the laws, including how they "may impact public safety," she said.
This week, Holder joined those who assert that the stand-your-ground laws make matters worse. Addressing the NAACP on Tuesday in Orlando, Fla., he declared that the laws may "contribute to more violence than they prevent."
"By allowing and perhaps encouraging violent situations to escalate in public, such laws undermine public safety," the nation's top law enforcement officer said.
Starting with Florida in 2005, at least 24 states have adopted some variation of a stand-your-ground law, Buchanan said. Additional states have adopted similar policies through state court rulings. Their general thrust is to remove the long-standing legal "duty to retreat" in the face of danger while in a public place. Instead, individuals may defend themselves, with lethal force if necessary, so long as they are in the public place legally.
Zimmerman's attorneys didn't specifically raise the stand-your-ground law as a defense against second-degree murder charges in the February 2012 death of Martin. The trial judge, though, did refer to the "right to stand your ground," under certain circumstances, in her instructions to the jury.
While Holder didn't cite any evidence in support of his assertion about the increased dangers posed by the laws, some exists.
Last year, two Georgia State University economics researchers concluded that the laws are "associated with a significant increase in the number of homicides among whites, especially white males." In a 55-page paper published by the National Bureau of Economic Research, authors Chandler B. McClellan and Erdal Tekin estimated that "between 28 and 33 additional white males are killed each month" as a result of these laws.
"These laws are also associated with a significant increase in emergency room visits and hospital discharges related to firearm-inflicted injuries," the Georgia State economists said.
Increased firearm ownership in states with stand-your-ground laws and the presence of bystanders-turned-victims in public places might account for the increased dangers, they suggested.
Texas A&M researchers Mark Hoekstra and Cheng Cheng reached similar conclusions last year in a 43-page study that found a "statistically significant 8 percent net increase in the number of reported murders and non-negligent manslaughters" in states with the enhanced self-defense laws.
From an economic perspective, Hoekstra and Cheng reasoned, the laws "reduce the expected cost of using lethal force," as the chances of civil or criminal liability are lowered. Consequently, the reasoning goes, individuals who are defending themselves are more likely to pull the trigger.
In some cases, though, the resulting violence is considered justified. In these cases, advocates say, the laws result in a safer society.
Private citizens committed 196 justifiable homicides nationwide in 2005, the year states began crafting stand-your-ground laws, according to the FBI's Uniform Crime Reporting system. The FBI defines justifiable homicide as "the killing of a felon, during the commission of a felony."
By 2011, the number of reported justifiable homicides had jumped to 260. In Florida, that number has nearly tripled since the years immediately prior to passage of the self-defense law.
In 2010, for instance, a 6-foot-4-inch ex-convict named Todd Edward Fryer aggressively approached a man who was sitting in a car in rural Marion County, Fla. The car's driver, 56-year-old Raymond Emala, pulled out a Colt .38 revolver. Fryer tried to hit Emala through the window, law enforcement officials later said, and Emala fired twice, killing Fryer. Three months later, the state attorney's office deemed it a justifiable homicide.
In some cases, the right data is simply hard to find.
The National Research Council, part of the National Academy of Sciences, cautioned in a 2010 report that it's very difficult to pin down how often a firearm is used defensively.
"This measurement problem has proved to be quite complex, with some estimates suggesting just over 100,000 defensive gun uses per year and others suggesting 2.5 million or more defensive gun uses per year," the group noted.
By Michael Doyle
McClatchy Washington Bureau