Jose Bustos, 18, has plead guilty to two counts of first-degree murder and one count of armed robbery, Maricopa County Attorney Andrew Thomas said Thursday.
In November 2005, Bustos entered a Subway restaurant at 43rd Avenue and McDowell Road armed with an AK 47.
Two employees closing the store handed Bustos $60 in cash and their cell phones. But one of them recognized Bustos and he shot both boys.
Bustos and co-defendants Jesus Jara, 17, and Marcos Ontiveros, 16, were arrested days later.