The judge says he agrees with prosecutors that the shooting may have been premeditated and added a special circumstance allegation of lying in wait.
A detective had testified that a collection of Nazi paraphernalia found in McInerney's room shows a deeper interest than the World War II book report the boy had been assigned.
Authorities say McInerney shot Larry twice in the head during a computer lab at E.O. Green Junior High School in Oxnard.
McInerney has pleaded not guilty to murder and a hate crime. He faces life in prison if convicted.