DENVER -- The death penalty phase of Sir Mario Owens' murder trial begins Monday.

Owens was convicted Wednesday on two counts of first degree murder. Because he is already serving a life sentence for a previous murder, some people question the wisdom of spending more money trying to put him to death.

"If he gets the death sentence, he won't be executed tomorrow," said Richard Dieter, Executive Director of the Death Penalty Information Center in Washington D.C. "He would be, at best, executed 10 to 15 years from now."

"There's no question death penalty cases cost more," said former Denver district attorney Norm Early. "But if you didn't go for the death penalty (in Owens' case) it would be in essence a free murder, you murdered someone and there was no additional punishment for that murder."

"If the case is a capital case, it's not a question about money," added former Adams County district attorney Bob Grant. "It's a question about the right thing to do. And apparently, the prosecution thinks the right thing to do is let Mr. Owens look the devil in the eye."

Dieter said the money it takes to prosecute and defend death penalty cases could be be used for other pressing needs.

"The costs are about $3 million more for execution cases than if a person is sentenced to life without parole," Dieter said.

"I don't care," Grant said. "Those figures are baloney."

The former district attorney said he understands that people opposed to the death penalty are passionate, but he added, "The debate over that issue should be rational, and it's not rational to assign fixed costs to capital cases."

Grant was the lead prosecutor in the Gary Davis murder case. Davis was convicted of the 1986 murder of Byers housewife Ginny May. He was put to death in 1997, and was the last person executed in Colorado.

"If it’s appropriately a case where the jury should make the decision whether this individual has forfeited his right to live in a civilized society,” Grant said, “then that cost is appropriate to be born by that society.”