I do not agree with the Death Penalty for many reasons, mainly because of its human rights implications, but also because I believe it is an 'easy way out' for those convicted of the worst crimes (murder, rape etc).
However, if convicted to a life behind bars, we are punishing the guilty to the fullest possible extent. Yes it may cost more to keep people locked up but it would be a much better deterent if life meant life because people would know what they were letting themselves in for and would never have a chance at parole.