George Zimmerman (left) and his attorney
appear in court for a bond hearing in June. Zimmerman's case sparked a
nationwide debate about so-called "stand your ground" laws.
If a stranger attacks you inside your own home, the law has always
permitted you to defend yourself. On the other hand, if an altercation
breaks out in public, the law requires you to try to retreat. At least,
that's what it used to do.
In 2005, Florida became the first of
nearly two-dozen states to pass a "stand your ground" law that removed
the requirement to retreat. If you felt at risk of harm in a park or on
the street, you could use lethal force to defend yourself. The shooting
of unarmed 17-year-old Trayvon Martin in Sanford, Fla., drew national attention to these laws.
researchers who've studied the effect of the laws have found that
states with a stand your ground law have more homicides than states
without such laws.
"These laws lower the cost of using lethal force," says Mark Hoekstra, an economist with Texas A&M University who examined stand your ground laws. "Our study finds that, as a result, you get more of it."
for the laws, like Republican state Rep. Dennis Baxley, who sponsored
Florida's version, says such legislation allows good people to defend
"They're doing what they are supposed to do, as a
good citizen," he says. "They're stopping a violent act. And that's what
I want the statute to do at the end of the day."
Hammer, a former president of the National Rifle Association, said the
laws have been effective and are working exactly as designed. A committee analyzing the Florida statute has found no increase in violence as a result of the law.
murder is a rare phenomenon, the numbers in any given state can be hard
to analyze. It can be difficult, for example, to disentangle the
effects of stand your ground statutes from other trends, such as natural
fluctuations in the crime rate. Until now, there has been little
attempt to rigorously study these laws at a national level.
This chart, based on data provided by Texas A&M
researcher Mark Hoekstra, compares homicide rates in states that have
stand your ground laws with homicide trends in states that don't have
the laws. The vertical y-axis represents an adjusted homicide rate that
takes into account a state's population, pre-existing crime trends and
To learn more about the data that went into this graph, please see this study
Hoekstra recently decided to analyze national crime statistics to
see what happens in states that pass stand your ground laws. He found
the laws are having a measurable effect on the homicide rate.
study finds that, that homicides go up by 7 to 9 percent in states that
pass the laws, relative to states that didn't pass the laws over the
same time period," he says.
As to whether the laws reduce crime
— by creating a deterrence for criminals — he says, "we find no
evidence of any deterrence effect over that same time period."
obtained this result by comparing the homicide rate in states before
and after they passed the laws. He also compared states with the laws to
states without the laws.
"We find that there are 500 to 700
more homicides per year across the 23 states as a result of the laws,"
he said. There are about 14,000 homicides annually in the United States
as a whole.
The fact that more people are being killed doesn't
automatically mean the law isn't working. Hoekstra says there are at
least three possible explanations.
"It could be that these are
self-defense killings," he said. "On the other hand, the increase could
be driven by an escalation of violence by criminals. Or it could be an
escalation of violence in otherwise nonviolent situations."
But which is it?
checked to see whether police were listing more cases as "justifiable
homicides" in states that passed stand your ground laws. If there were
more self-defense killings, this number should have gone up. He also
examined whether more criminals were showing up armed.
cases, he found nothing. There were small increases in both numbers, but
it was hard to tell whether there was really any difference.
if the numbers on justifiable homicide and criminals using lethal force
don't explain the rise in homicide, what's causing the increase?
possibility for the increase in homicide is that perhaps [in cases
where] there would have been a fistfight ... now, because of stand your
ground laws, it's possible that those escalate into something much more
violent and lethal," says Hoekstra.
It's important to remember
that the data Hoekstra is analyzing depend on how police classify
shootings. Police guidelines likely vary from state to state, and police
in different places may be interpreting shootings differently in light
of stand your ground laws.
Still, based on the available data,
it appears that crafters of these laws sought to give good guys more
latitude to defend themselves against bad guys. But what Hoekstra's data
suggest is that in real-life conflicts, both sides think of the other
guy as the bad guy. Both believe the law gives them the right to shoot.
In a separate analysis
of death certificates before and after stand your ground laws were
passed in different states, economists at Georgia State University also
found that states that passed the laws ended up with a higher homicide
That study also tracked the increased homicides by race.
In contrast to the narrative established by the Trayvon Martin shooting —
many people believe black men are more likely to be the victims of
stand your ground laws — this analysis found the additional deaths
caused by the laws were largely concentrated among white men.
NRA, which has backed these laws, referred a request for comment to
Howard Nemerov, a gun-rights activist who often represents the NRA
viewpoint on television. Nemerov offered a technical analysis, which has
not been reviewed by academic experts, in which he said concerns about
the law were flawed.
Stanford law professor John Donohue,
on the other hand, praised the study done by Texas A&M's Hoekstra.
Donohue has been studying crime and violence for more than two decades
and is working on his own independent analysis of stand your ground
laws. So far, he says, he's getting the same results Hoekstra did.
imperfect but growing evidence seems to suggest that the consequences
of adopting stand your ground laws are pernicious, in that they may lead
to a greater number of homicides — thus going against the notion that
they are serving some sort of protective function for society," he says.
And in murder cases, Donohue says, the laws might end up being a refuge for some defendants.
been hearing from defense lawyers around the country that if they
happen to have a criminal defendant in a stand your ground jurisdiction,
pretty much no matter what happens, you can say, 'Well, I shot the guy,
but I felt threatened and had a reasonable basis for fearing injury to
myself,' " he said.