While there was no question that the attack occurred, and that some neighbors ignored cries for help, the portrayal of 38 witnesses as fully aware and unresponsive was erroneous. The article grossly exaggerated the number of witnesses and what they had perceived. None saw the attack in its entirety. Only a few had glimpsed parts of it, or recognized the cries for help. Many thought they had heard lovers or drunks quarreling. There were two attacks, not three. And afterward, two people did call the police. A 70-year-old woman ventured out and cradled the dying victim in her arms until they arrived. Ms. Genovese died on the way to a hospital.

But the account of 38 witnesses heartlessly ignoring a murderous attack was widely disseminated and took on a life of its own, shocking the national conscience and starting an avalanche of academic studies, investigations, films, books, even a theatrical production and a musical. The soul-searching went on for decades, long after the original errors were debunked, evolving into more parable than fact but continuing to reinforce images of urban Americans as too callous or fearful to call for help, even with a life at stake.

Psychologists and criminologists called the reluctance of witnesses to involve themselves the “bystander effect,” or the “Kitty Genovese syndrome.” Studies discerned a “diffusion of responsibility,” finding that people in a crowd were less likely to step forward and help a victim. Some communities organized neighborhood-watch patrols. In New York, an emergency call to the police was simplified later in 1964 — from dialing “O” for operator or a precinct or a borough headquarters, to a central police number. The unified 911 system was not established until 1968.

Mr. Moseley seemed an unlikely serial killer. Soft-spoken, intelligent, with no criminal record, he was 29, a married father of two who owned his home in South Ozone Park, Queens, and operated business machines in Mount Vernon, N.Y. Later, in confessions and testimony, he said he had driven around late at night seeking victims, and had killed three women, raped eight and committed 30 or 40 burglaries.

He had been cruising around for more than an hour on March 13, 1964, when, around 3:15 a.m., he encountered Catherine Genovese, known as Kitty, the manager of a bar in Hollis, Queens, as she was driving home after work. He followed her to the parking lot of the Long Island Rail Road station in Kew Gardens, near a faux-Tudor building on Austin Street, where she shared an apartment with another woman.

He followed her on foot as she walked toward her building, heading for its residential entry in the rear. She saw him coming and, frightened, ran. He chased her, caught up with her outside a darkened bookstore and, by his own account, stabbed her twice in the back with a hunting knife.