In the wake of a number of shocking mass shootings, Americans should call on their elected leaders to tackle the problem of easy access to guns for people who have no business being armed.

Ever since the Virginia Tech killings in mid-2007 by a mentally ill college student, the need has been obvious to tighten laws to prevent such troubled individuals from obtaining gun licenses. But doing so bucks against the powerful gun lobby.

Now a disturbing new study from a Washington-based gun control group, the Violence Policy Center, should sharpen that debate - and maybe even drown out the expected protests from the National Rifle Association.

In a report released this month, the center found that the shooting deaths of 67 people - including eight law enforcement officers - had been attributed to people holding legal gun permits. In 10 incidents, the shooters also took their own lives during a murder-suicide, and eight were mass shootings with three or more victims.

The report covers the two-year period from May 2007 through October 2009, not including the Nov. 5 killing of 13 people in Texas. In that most recent mass killing, Army Maj. Nidal Malik Hasan is charged with emptying two handguns in a crowded Fort Hood troop-processing center.

All of the shooters - who were identified from news accounts - held legal permits to carry a concealed handgun. As a result, the Violence Policy Center contends that "contrary to the false promises of the gun lobby, the simple and deadly fact is that state concealed-handgun systems are arming cop-killers, mass shooters, and other murderers."

That's certainly a serious concern for a state like Pennsylvania, which has some of the least restrictive gun laws. Indeed, one of the most tragic shootings of law officers occurred in Pittsburgh this past spring, where white supremacist Richard Poplawski allegedly shot and killed three police officers in April.

New Jersey long has been a better model for tightly controlling access to legal handguns. The state's main gun problem is fighting the flow of illegal weapons, many of them funneled into Camden and other cities by traffickers who acquire weapons through illegal "straw" purchases in Pennsylvania and other states.

Illegal trafficking remains the bigger problem, to be sure. But the carnage wreaked by legal gun owners calls into question a frequent defense of concealed-carry laws - that they make the streets safer, since the bad guys know the good guys are packing heat.

Apart from the greater risk of shootings in the home whenever weapons are present, the high-profile murders committed by a relative handful of legal gun owners indicate that the wrong people still are being allowed to obtain guns legally.

Find data on the shootings at