Now such events seem to happen with numbing regularity. Aurora and Newtown aren't even the only mass shootings of the past six months. In August, a gunman attacked a Sikh temple in Wisconsin, murdering six. Earlier this week a gunman killed two people — and was intent on killing more — at an Oregon shopping mall.

Adam Lankford, a criminal justice professor at the University of Alabama, wrote last summer in The Huffington Post that four of the 10 deadliest mass shootings in U.S. history had occurred in the past six years. He mentioned Aurora, "Nidal Hasan's attack at the Fort Hood Army base in 2009, Jiverly Wong's attack at a Binghamton immigration center in 2009, and Seung-Hui Cho's attack on the Virginia Tech campus in 2007."

Now the tally must be adjusted: Five of the worst shootings have occurred in just six years.

Editorial, The Denver Post,

So we're left with what we do know: Firearms make it easier to commit mass homicides. Some killers, but not all, leave a trail of warning signs. Societal attitudes toward violence, reflected in video games and movies and music, may be factors. And we as a society are better at blaming causes than creating solutions.

Hug your children and your parents and your grandparents today. Tell them you love them. Spend time with one another. Nurture one another.

Grieve for the families who are in mourning.

Grieve for an angry, violent society that has lost its way.

And find a way to turn your mourning into positive action. Do what you can to make your corner of the world a more rational place.

Editorial, The Statesman Journal, Oregon,