California's gun control is very strict, and Gao Guang needs to obtain some documents before he can purchase a firearm.
Gao Guang had already received his Firearm Safety Certificate, also known as the FSC, which he could take at the gun store and shooting club where he practiced shooting.
The FSC exam mainly consists of common sense regarding the safe use of firearms, with ten true or false questions and twenty multiple-choice questions making up the thirty questions in total. Answering twenty-three correctly would result in a pass, and Gao Guang got all thirty correct.
Then Gao Guang also obtained a shotgun certificate by taking ten hours of class at the gun store, after which he passed the exam where eighty correct answers out of a hundred would suffice, but again, he answered all questions correctly.