Daniel Wayne Cook was the fifth person to be executed in Arizona this year, the Tucson News Now Web site reported.
Cook was given a lethal injection and was pronounced dead at 11:03 a.m., just hours after the U.S. Supreme Court rejected his final appeal.
Cook killed raped and tortured Carlos Cruz-Ramos, 26, and Kevin Swaney, 16, before killing them in Lake Havasu City in July 1987, Today's News-Herald in Lake Havasu City said.
A co-defendant, John Matzke, admitted his role in Ramos' death and was released in 2007 after serving a 20-year prison term, the newspaper said.
All four had worked at Bob's Big Boy's Restaurant.
Tucson News Now said the staff at the prison in Florence where Cook was executed said the inmate's final statement expressed remorse.
"I'd like to say sorry to the victim's family," the statement said. "I know that's not enough ... . (significant pause) ... Where am I? To my lawyers, thank you. Red Robin, yum. I'm done. I love you."
Cook's last meal Tuesday night included eggplant lasagna, garlic cheese mashed potatoes, roasted Brussels sprouts, broiled asparagus, root beer and ice cream, the news Web site said.