Orange County Superior Court Judge John Conley followed the recommendation of a jury that in January decided that Daniel Patrick Wozniak, 32, should be put to death after deliberating for just an hour.
Jurors had convicted Wozniak of the murders in December.
'At the cost of two human lives, the defendant chose not to get married inexpensively or to defer his honeymoon. He wanted to do it in style, and he was willing to kill two people he knew to accomplish this,' Conley said.
Wozniak was debt-ridden in 2010 when he shot a neighbor, Samuel Herr of Costa Mesa, to steal $50,000 the Army veteran had saved from service in Afghanistan, prosecutors said.
Wozniak then used a ruse to kill Herr's friend, Julie Kibuishi, and tried to make it appear Herr had raped and killed her, then fled, prosecutors said.
He also dumped Herr's dismembered body in a park. The scheme unraveled, and Wozniak was arrested days later.
The likelihood Wozniak will be executed anytime soon is slim because of challenges over the California's death penalty.
No one has been put to death since 2006, and there are nearly 750 inmates on death row at San Quentin, where he is now headed.