The 16-year-old Ordonez is scheduled to be sentenced May 21.
Ordonez is accused of killing 24-year-old Orlando Pizzaro last April in El Remolino grocery store.
Police said Pizzaro and Ordonez, then 15, exchanged words. They said Pizzaro pushed Ordonez in the face, then Ordonez pulled out a gun and shot Pizzaro twice before a friend of Pizzaro's knocked the gun to the floor.
