The
 headlines in the case were sadly familiar. An angry adult armed with a 
gun used it to shoot and kill an unarmed black teenager he thought 
seemed “bad”—this time, because the teenager and his friends were 
sitting in a car listening to music the grownup didn’t like. In this 
outrageous Florida case, a middle-aged white man, Michael Dunn, was 
convicted of three counts of attempted murder and one count of shooting a
 gun into an occupied car. Jurors agreed he faced no threat after he was
 annoyed by loud music -- coming from a car he had deliberately chosen 
to park next to -- and then started an argument, pulled a gun on the 
car’s black teens, and fired three shots at the young men inside the car
 as they tried to drive away from him. 
But
 the jury could not agree on the most serious charge of first-degree 
murder for shooting the first seven bullets at the stationary car and 
hitting 17-year-old Jordan Davis in his lung, liver, and aorta. 
Florida’s notorious “Stand Your Ground” law, which gives gun owners a 
license to kill if they feel threatened, was allegedly enough for three 
jurors to vote against conviction. At least one juror said she believed 
Michael Dunn did get away with murder: “There is no longer a Jordan 
Davis, and there is only one reason why that is. The boy was shot and 
killed for reasons that should not have happened.”
In an interview with Good 
Morning America Jordan’s mother, Lucia McBath, said she believed the 
jurors in her son’s case did the best they could with the laws they had,
 but also made it clear she believes our nation’s existing laws did not 
protect Jordan or millions of other victims of gun violence in America. 
When asked what justice for her son would look like she answered:
“Justice for Jordan will be, 
ultimately, really when we change the laws. Because that will be not 
just justice for Jordan, and justice for Trayvon, and justice for all 
the children at Sandy Hook, and justice for Aurora, and justice for 
Virginia Tech, and the Navy Yard -- it will be justice for everyone that
 has suffered because of these laws, and will continue to suffer. So 
once the laws are changed, that’s the ultimate justice for all.”
Researchers at Texas A&M 
University studied the impact of Stand Your Ground laws, like the one 
enacted in Florida in 2005, across the country and concluded in a 2012 
study that “the laws do not deter burglary, robbery, or aggravated 
assault” but do “lead to a statistically significant 8 percent net 
increase in the number of reported murders and non-negligent 
manslaughters.” Evidence is also clear that these laws have a disparate 
racial impact. Researchers from the Urban Institute found that when 
White shooters kill Black victims, 34 percent of the homicides are 
deemed justifiable, while only 3.3 percent are ruled justifiable when 
the situation is reversed.
Now researchers from the 
Johns Hopkins Center for Gun Policy and Research have released the 
results of a new study on the effectiveness of another crucial segment 
of our nation’s gun laws: those requiring background checks before 
purchasing a gun. For this study the scholars took a close look at the 
state of Missouri’s 2007 repeal of its permit-to-purchase law. Before it
 was repealed this law required all handgun purchasers in Missouri to 
obtain a license verifying that they had passed a background check. The 
researchers wanted to know what happened when this requirement was taken
 away -- and they learned that repealing that law has led to a 16 
percent increase in Missouri’s murder rate. The study showed between 
2008 and 2012 there were an additional 55 to 63 murders in Missouri each
 year associated with the law’s repeal. During those same years, the 
national murder rate dropped by over 5 percent.
The research controlled for 
changes in policing, incarceration, burglaries, unemployment, poverty, 
and other laws adopted during the study period that could affect violent
 crime. The spike in murders only occurred for murders committed with a 
gun and happened statewide, while bordering states showed no increase. 
The number of handguns recovered from scenes of crimes or from criminals
 quickly doubled after the repeal. In a press release, lead author 
Daniel Webster, ScD, MPH, director of the Johns Hopkins Center for Gun 
Policy and Research, said: “This study provides compelling confirmation 
that weaknesses in firearm laws lead to deaths from gun violence.” 
Co-author Jon Vernick, JD, MPH, deputy director for the Center for Gun 
Policy and Research, added:
“Because many perpetrators of
 homicide have backgrounds that would prohibit them from possessing 
firearms under federal law, they seek out private sellers to acquire 
their weapons. Requiring a background check on all gun sales is a 
commonsense approach to reducing gun violence that does not infringe 
upon the Second Amendment rights of law-abiding gun owners.”
Requiring a background check 
seems like common sense to most Americans -- and yet some lawmakers 
refuse to make it happen. Others, like those in Missouri, are actually 
moving backwards. The same press release noted:
“Only fifteen states require 
individuals purchasing handguns from unlicensed sellers to pass 
background checks, with ten of these states requiring all purchasers to 
acquire a permit-to-purchase license. A 2013 public opinion survey from 
Johns Hopkins found the majority of Americans (89 percent) and gun 
owners (84 percent) support requiring a background check system for all 
gun sales. The majority of Americans (77 percent) and gun owners (59 
percent) also reported supporting requiring people to obtain a license 
from a local law-enforcement agency before buying a gun to verify their 
identity and ensure that they are not legally prohibited from having a 
gun.”
This latest Johns Hopkins 
study is another key step in finding out what works to reduce gun 
violence. The available evidence is clear: Stand Your Ground laws do not
 reduce gun violence. Background checks do -- just one part of a network
 of solutions that can help. We need a robust commitment to much more 
research on the epidemic public health threat of gun violence to 
identify all of them. And when we know what works, we need leaders who 
will listen to and act on the research and public opinion to preserve 
lives. We do not need any more suffering families. Jordan Davis’s father
 Ron said:
“All the other 17-year-olds 
out there -- they shouldn’t have to fear the adults with the guns that 
are running around here shooting them at will. If you throw popcorn in 
someone’s face, they want to shoot you because you threw popcorn in 
their face. That’s what we’ve come to. But we have to stop.”
We really do have to stop!