A maid called the police at 9 a.m. on Aug. 9, 1969, after finding five dead people in a Beverly Hills home. There was a blond woman on the living room floor, a rope wrapped around her neck and stab wounds in her swollen belly. A bloodied corpse wore a hood; another was behind the wheel of a car. Two more were sprawled on the lawn about 50 feet apart. A neighbor recalled hearing shots around midnight.

The word “pig” was wiped in blood on a white front door.

Charles Manson, an ex-convict turned cult leader, had planned the attack, directing his followers to sneak into a Benedict Canyon home rented by the director Roman Polanski, where they killed his pregnant wife, Sharon Tate, and four guests before dawn.

Americans have long had an insatiable appetite for gruesome crime stories. But this inexplicable act left many in Hollywood panicked that they could be next.

Some celebrities bought handguns to protect themselves. Others installed security cameras or holed up at the Beverly Hills Hotel. For many, the killings exposed the network of hustlers and hangers-on who lurk in the shadows of Los Angeles, barely within grasp of celebrity culture and the desire that fuels it.