John Earnest, 20, had no reaction when San Diego Superior Court Judge Peter Deddeh made the ruling.
Attorneys presented evidence Thursday including a chilling surveillance video of Earnest allegedly walking into the synagogue and opening fire back in April.
Earnest will also be tried on an arson charge for a fire at a nearby mosque that happened before the synagogue shooting.
Earnest could face the death penalty if he is convicted of murder as a hate crime, although prosecutors haven't said whether they will pursue capital punishment.