SACRAMENTO — Throughout 1977, the terrified residents of Sacramento County wanted to know when their horror movie of an existence would end. In packed community forums, they expressed their fears about the sadistic predator who was committing sexual assaults in their previously tranquil neighborhoods every few days — someone nicknamed the East Area Rapist.

At one gathering, in a school cafeteria, a Sacramento sheriff’s detective named Carol Daly gave a brief tutorial about defending oneself against the attacker. But before the few hundred audience members dispersed into the California night, a man questioned how anyone could possibly get away with raping a woman in the presence of her husband, who would do everything in his power to prevent an assault.

A few months later, the East Area Rapist targeted that very man and his wife, in one of the more brutal attacks of the dozens he had committed. Ms. Daly, now retired, said on Friday that she has no doubt:

“The rapist was there at that meeting.”

The horrifying moment reflected how the meticulous criminal — whom investigators strongly suspected had law enforcement connections — taunted his pursuers with catch-me-if-you-can brio. He was flaunting his power, it seemed, as well as his belief that he could elude accountability forever.