At first glance, California's Senate Bill 553, aimed at preventing and addressing workplace violence, may not appear directly relevant to workplace investigations. However, within the legislation's key provisions is a requirement for employers to perform an investigation after any threat or incident of workplace violence. This mandate mirrors the Fair Employment and Housing Act (FEHA), which imposes an obligation on employers to conduct impartial investigations when complaints of discrimination, harassment or retaliation arise. This article will provide an overview of the new legislation, discuss the mandate for investigations, and explain why an external attorney investigator may be best situated to perform them.