Good point. They say lock them up for life, with no parole, but while rare, prisoners can escape.
And California has to bear the burden of paying to incarcerate those on death row. We now have 667 people on death row, and no executions in sight as far as the eye can see.
http://www3.signonsandiego.com/stories/2009/mar/11/ca-brown-death-penalty-031109/?zIndex=65488