California Code, Education Code - EDC § 49394

(a) Upon the notification described in Section 49393, the local law enforcement agency or the schoolsite police, as described in paragraphs (1) and (2) of subdivision (a) of Section 49390, as appropriate, with the support of the local educational agency, shall immediately conduct an investigation and assessment of any threat or perceived threat described in subdivision (e) of Section 49390.

(b) The investigation and threat assessment under subdivision (a) shall include a review of the firearm registry of the Department of Justice.

(c) The investigation and threat assessment under subdivision (a) shall include a search conducted at the schoolsite, only if the search is justified by a reasonable suspicion that it would produce evidence related to the threat or perceived threat.