Investigators found amunition and explosives at the couple's house. Farook and his wife Malik left their six-month old infant with Farook's mother before going to the center on Wednesday.
Law enforcement agencies are investigating if Malik, who hails from Pakistan, was the brains behind the attack.
Anjem Choudary with another suspect pleaded "not guilty" before the magistrate.
The leader of the terrorist group calling itself the Islamic State has called for terrorist attacks in Saudi Arabia, less than a week after rumors of his death in a U.S.-led coalition airstrike.
