One more reminder of how guns escalate ordinary disputes into deadly finality. Yesterday in Philadelphia,

Tyrirk Harris, 28, was sentenced for the February 2012 shooting death of a neighbor who confronted him for not cleaning up after his German shepherd and Chihuahua. Prosecutors said Harris pulled a gun and shot 47-year-old Franklin Manuel Santana once in the face and four times in the back.

"There were dog feces on several of the neighbors' yards. That's what led to this particular confrontation," Philadelphia Police Chief Inspector Scott Small told NBC Philadelphia shortly after the crime. Police said the two had an ongoing dispute about the dogs.

You could say, "Guns don't kill people. Dog feces kills people." But more seriously: guns make killers of people who woke up that morning with no plan at all to do harm to anyone.