Ricardo Leyva Muñoz Ramirez, known as Richard Ramirez, dubbed the Night Stalker, the Walk-In Killer and the Valley Intruder, was an American serial killer and sex offender whose crime spree took place in California from June 1984 until his capture in August 1985. He was convicted and sentenced to death in 1989, and died while awaiting execution in 2013.

The Tenderloin is a neighborhood in downtown San Francisco, in the flatlands on the southern slope of Nob Hill, situated between the Union Square shopping district to the northeast and the Civic Center office district to the southwest. Encompassing about 50 square blocks, it is historically bounded on the north by Geary Street, on the east by Mason Street, on the south by Market Street and on the west by Van Ness Avenue. The northern boundary with Lower Nob Hill has historically been set at Geary Boulevard.