Keller @ Large: Death Penalty For These 3

BOSTON (CBS) - Call it a confluence of evil - three of the most vicious, calculating mass murderers I've ever experienced are all in the news at the same time.

Down at federal court Wednesday, a jury heard closing arguments for and against the death penalty for Gary Sampson, a career criminal who went on a killing spree back in 2001, slaughtering three innocent bystanders unfortunate enough to cross his path.

Sampson's lawyer said in advance he intended to quote Dr. Martin Luther King Jr.'s statement that "returning violence for violence multiplies violence," a reference to the political tactics King employed to shame the nation into action on civil rights.

However, there is zero evidence that removing Sampson from our prisons permanently would leave behind a more-violent world.

Also in the headlines these days, Dylann Roof, the bitter young racist who walked into a Charleston church two years ago and murdered nine black worshipers.

Deemed mentally competent to stand trial by the judge, Roof told the jury "there's nothing wrong with me psychologically," and I think we should take him at his word. Pure evil exists, and it's hard to see how justice would be served by watching this specimen eat three squares a day for the next 70 years.

And finally, we are being subjected to yet another round of news stories about bloodthirsty killer Charles Manson, receiving taxpayer-funded medical treatment to help prolong his miserable 82-year life.

Capital punishment is a difficult issue. I can respect opposition on moral grounds. But good luck making the case that there's any social benefit in keeping any of these three around.