When he was district attorney of Los Angeles more than a decade ago, Gil Garcetti was for the death penalty. While he himself never tried a death penalty case, his office prosecuted more than any other county in California. That was a point of pride at least back then. Had he not been pro-death penalty, there is very good reason to believe he never would have been elected.

Garcetti has now joined a new coalition that is trying to end the death penalty in California, arguing that it serves no purpose and unnecessarily taxes the system, imposing costs that would better be spent solving crimes and supporting efforts to keep kids from going into crime in the first place.

Have the times changed, or has Garcetti?

My guess is some of both.

Garcetti's starting point is that the death penalty doesn't work, that it does not deter crime. There are certainly studies that confirm this. There are also studies that don't. My own research confirms that both sides can point to studies. Anti-death penalty advocates argue that it didn't deter the 600-plus murderers who are being held in isolation in expensive death row cells. Pro-death penalty advocates argue that you just can't know how many bad guys did not pull the trigger.

The morality of the death penalty is, of course, a personal decision. If you believe it is wrong for the state (or the federal government) to take a life under any circumstances, then the deterrence debate doesn't matter.

That is not what I believe. I can think of plenty of really bad guys -- think 9/1 1 plotters -- who have no right to live. My view has always been that the death penalty puts much-needed pressures on the system to not make mistakes and to ensure proper procedures are followed -- in short, to get it right.

At least three things have changed in 10 years.

First, the advent of DNA evidence has eliminated one of the most common sources of mistakes in the system. We don't get the wrong guy anymore, or at least we shouldn't. Mistakes that were made decades ago -- we read those headlines all the time, even though they are very much an exception and not the rule -- shouldn't be made again. There's an argument in favor of the death penalty.

Second, the notion that death penalty cases would bring out the best in the system -- the best lawyers arguing in carefully selected cases with judges carefully and deliberately ensuring that justice is served -- has also proved to be overly optimistic.

Third, the political climate has changed. In the '80s and '90s, support for the death penalty was the litmus test for being "tough on crime," and being "tough on crime" was a prerequisite to winning. It was not a major issue in the 2008 presidential election, which resulted in the first anti-death penalty president in at least 30 years.

The most troubling aspect of Garcetti's argument -- or, depending on your view, the most persuasive -- is his claim that the money being spent to house these prisoners (who, by definition, have very little to lose by prison savagery) and provide them with more lawyers and more hearings than anyone else could better be spent solving murders and rapes. According to Garcetti's figures, nearly half of all murders and more than half of all rapes are never solved. And this brings me to my bottom line.

I don't know about the death penalty, but I do know this: Swift and certain punishment, even if it is only life imprisonment, is a far more effective deterrent than an even shot at getting away with it. If I had my way, that's what we'd be discussing right now, separate and apart from the overheated rhetoric that tends to accompany debates about the death penalty.