WHATEVER REASON we eventually settle on for the latest deadly shooting spree, this time in Montgomery County yesterday - mental illness, easy access to guns, a world gone mad - we know one thing for sure:

A gun shattered families, a community and our sense of safety.

A gun.

Again.

Just hours after the second anniversary of the Sandy Hook Elementary School shootings in Newtown, Conn., that left 26 people dead, including 20 children, and in the midst of a siege in Sydney, Australia, that eventually ended with three dead, including the assailant, another shooting spree unfolded closer to home.

Police said Bradley William Stone, 35, a military veteran with post-traumatic stress disorder, killed six family members, including his ex-wife, Nicole A. Stone.

The mayhem apparently was sparked by a contentious custody battle. So desperate was this man to take his children from his ex-wife that he allegedly used deadly force to separate them.

And now the young girls, who likely witnessed their mother's execution and whom Stone took from their mother's home in Lower Salford Township but were found unharmed - physically, anyway - are left without a mother.

And we are left with the all-too-familiar set of sorry questions:

Why?

How?

Again? Not again.

Two years after the Newtown massacre, the still-unfathomable moment that was supposed to change everything and that should have changed something, nothing has changed.

The proof is in the bloodshed.

There are 32,000 gun deaths in the United States, on average, every year. Two years after a troubled young man shot 20 children and six adults in Newtown - including my friend's daughter, teacher Lauren Rousseau - school shootings in the U.S. continue at a rate of nearly one a week, according to Everytown for Gun Safety and Moms Demand Action for Gun Sense in America.

"After the tragedy, many politicians in Washington said how outraged they were, how sorry they were, and how they would honor those 20 beautiful children by making everyone else's safer," former U.S. Rep. Gabrielle Giffords, who survived a mass shooting in 2011, said in a statement marking the second anniversary.

"But then Congress did something truly remarkable: nothing."

And we, the American people, have clearly decided that we are OK with that.

A year after the deadly school massacre, a Pew study found more support for regulating firearms. But fast forward another year, and the sickening memories of butchered babies apparently have faded.

For the first time in more than two decades of Pew Research surveys, the center said there is more support for gun rights than gun control. The real problem, many Americans think, is mental illness, not lack of gun control.

Except two Vanderbilt University researchers who have challenged the assumptions about gun violence and mental illness in a recent study say it's not the "crazy" person whom we have to fear.

Fewer than 5 percent of the 120,000 gun-related killings in the United States between 2001 and 2010 were perpetrated by people diagnosed with mental illness, they write.

"People are far more likely to be shot by relatives, friends or acquaintances than they are by lone violent psychopaths," Dr. Jonathan Metzl and Kenneth T. MacLeish write in their article, "Mental Illness, Mass Shootings and the Politics of American Firearms."

And while it may be easier to blame the gun violence on the troubled kid getting his revenge for perceived slights, the guy who was off his meds, the damaged vet with PTSD, the researchers say it misdirects people from factors that do more to predict gun violence: drug and alcohol use, history of violence, access to firearms and personal relationship stress.

Stone, who neighbors said terrified his ex-wife, is a former Marine reservist who served in Iraq. He also has three DUI convictions, most recently a February 2013 arrest for driving while intoxicated with a blood-alcohol level more than twice the legal limit.

"We should set our attention and gun policies on the everyday shootings, not on the sensational shooting because there we will get much more traction in preventing gun crime," Metzl said in a Science Daily story.

In a social-media sign-of-the-times moment yesterday, Twitter users following the developments in Montgomery County asked reporters to use the hashtag #montcoshooting.

We're getting much better at following horror in real time.

We're just not getting any better at doing anything to keep it from happening.

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