Feb. 2009 CBS News - Study shows death penalty deters murder.

"It has not been shown that the death sentence would be materially more effective to deter or prevent murder than the alternative sentence of life imprisonment would be."

Holly - in point one you made do you mean "deters murder"?

Rational opponents rightly point out that no one has yet shown that executions deter murder.

He went on, "The court's decision will not deter the D.E.A.'s commitment to investigate all those responsible for the kidnap and murder of special agent Enrique Camarena."

Death penalties don't deter murder.

The death penalty has nothing to do with deterring murder.

Later in his career, as a defense lawyer, he opposed capital punishment, saying it did not deter murder.

But capital punishment doesn't even deter ordinary murder.

"I think Governor Pataki is sincere when he says that the death penalty deters murder," he said, "but I haven't seen any proof of that yet."