I've been away from the blog. A long end-of-year vacation was followed by a bout of bronchitis that kept me out of work for several days. Then, it was right back into court to cover the latest trial in the Catholic clergy sex-abuse scandal.

Guns and gun crimes continue dominating the news but two cases this month got my attention because the killers used the oldest weapon in the book. Before Cain brained Abel with the jawbone of an ass, there was the human fist and these two Philly cases showed just how easy it is to cross the line from assault to homicide.

The first case was the Jan. 4 guilty plea and sentencing of one of three men charged in the Jan. 14, 2012 killing of Kevin Kless during an early-morning altercation in Old City.

Police said Kless, 23, a bright, talented Center City insurance executive and freshly minted grad of Temple's Fox School of Business, and his girlfriend and another female friend were walking at Fourth and Chestnut after an evening of clubbing in Old City. At about 2:30 a.m. Kless tried to hail a cab and cursed loudly when the taxi kept going.

If Kless' curses were lost on the cabbie, they hit home with three men in a car behind the cab who thought the words were aimed at them. Two men left the car, surprised Kless and began hitting him. They finished, left Kless standing and went back to the car. Their companion, the driver, then walked up and punched Kless once in the head.

For Kless, it could have been nothing more than the start of a long night's journey into day. Instead, the single punch authorities say was thrown by 21-year-old Steven Ferguson, of Fox Chase, tore a blood vessel in his Kless' neck. Kless, say authorities, was essentially dead before he hit the ground.

Ferguson and Kenneth Enriquiz-Santiago, 20, of Juniata Park, are awaiting trial for third-degree murder. Enriquiz's cousin Felix Carrillo, 24, of Olney, who was just shy of a business degree from Philadelphia Community College, pleaded guilty to involuntary manslaughter and was sentenced to two to five years in prison.

A week later and 23-year-old Gerard Shaffer Jr. was in front of a Philadelphia Common Pleas Court jury, sobbing his way through an effort to convince jurors that he did not mean to kill a 54-year-old alcoholic pedestrian during a road-rage confrontation between the pedestrian and Shaffer's father.

The incident that ended in Mark Wallace's death began about 7:30 p.m. on April 8, 2010. Witnesses testified that Wallace was crossing the intersection and walked in front of Shaffer Sr.'s gold Dodge Durango, stopped eastbound on Fairdale at the light.

Shaffer began honking his horn and swearing at Wallace to get out of the way; Wallace yelled back that "I have the right of way."

Witnesses said Shaffer Sr. parked the SUV, got out and pursued Wallace on foot north on Knights Road and confronted him at the entrance to a gas station. Wallace held his hands up and backed away, witnesses testified, repeating that he "had the right of way." Shaffer pushed Wallace in the chest and knocked him back several steps. Wallace approached and threw a punch and the pair started fighting.

Shaffer Jr. got out of the SUV and ran to the fight calling after his father. The younger Shaffer testified that he grabbed Wallace and they fell to the ground; Wallace apparently struck his head and became unconscious. Witnesses said Shaffer Jr. pushed his father out of the way, grabbed Wallace in a bear hug and flipped him over his shoulder and headfirst into the concrete.

Wallace, according to the autopsy, died of massive brain injuries.

On Jan. 14, the jury found Shaffer Jr. guilty of involuntary manslaughter rather than third-degree murder. He still faces up to five years in prison when he is sentenced on March 8. His father died of a heart attack before he could be tried.

Philadelphia police statistics say the homicides of Kevin Kless and Mark Wallace are among less than five-percent of all killings. No surprise: guns are the weapons used in the overwhelming majority of murders.

So what's the take-away from this? The human body, for all its resilience, is also incongruously fragile. If popular culture makes gunplay seem without consequence, fisticuffs seem positively benign. The reality is that guns are more efficient but the impact of a single punch – regardless of intent or provocation – can be just as deadly.