Ricardo "Richard" Leyva Muñoz Ramirez (/rəˈmɪərɛz/; February 29, 1960 - June 7, 2013), dubbed the Night Stalker, the Valley Intruder (as his attacks were first clustered in the San Gabriel Valley), and the Walk-In Killer was an American serial killer and sex offender whose crime spree took place in California.