On April 24, 1981, New York Daily News reporter Brian Kates got a grisly assignment. He was to investigate the death of an elderly woman, believed homeless, who had been brutally stabbed to death the night before in Manhattan's Hell's Kitchen. Her name, Kates would find out, was Phyllis Iannotta; her age, 67; her property, a bag of Martinson's coffee, a vial of Tempo perfume, a ball of dirty white yarn, two shabby cardigan sweaters, an empty box of Sloan's liniment, a can of Friskies turkey-and-giblet cat food and a plastic spoon.

The death of a shopping bag lady, like the death of a junkie, is what journalists call a "cheap homicide"; Phyllis Iannotta had no ties to the community and her death was not particularly newsworthy. Kates' report appeared on Page 5 the next day. But unlike other stories, this one haunted Kates; he wanted to know what circumstances led to Iannotta's homelessness and homicide, and he set about reconstructing her life. The fruit of his diligent digging is "The Murder of a Shopping Bag Lady," a sad account of one woman's decline from normalcy and an indictment of society for abandoning its neediest citizens.

Street people do not leave behind many documents, so it is quite extraordinary that Kates was able to piece together this biography. Born Filomena Iannotta in a small town north of Naples, Phyllis emigrated as an infant with her parents to Brooklyn; she attended public schools but dropped out during the Depression to supplement her father's meager earnings as a junkman. She had a spotty work history, according to Social Security records, holding no less than 40 jobs -- mostly on assembly lines -- over 22 years; nevertheless she provided for her parents and generally improved her lot, managing even to help out her ne'er-do-well baby brother. From the reports of former classmates, coworkers and landlords, we know that Phyllis was vivacious and smart, an aficionado of crossword puzzles and ballroom dancing.

Then in 1963, things fell apart. Jilted after a two-year affair with a married man, Phyllis became withdrawn; she became sloppy; she stopped working and stopped paying the rent. Although there were periods of stability following this breakdown, they were short-lived. She was eventually hospitalized with the diagnosis of paranoid schizophrenia; released after a month with a prescription for Thorazine, she became increasingly delusional and started setting fires in her apartment. When she was evicted in the winter of 1977, she was 63, an age at which most people are contemplating retirement; and she was on the streets for good.

Kates did not stop with Phyllis Iannotta's story. He spent time himself sleeping on park benches, and he worked as a volunteer at the Dwelling Place, a shelter for homeless women. What he documents is the utter humiliation suffered by women who never suspected they would end up on the streets: a former Long Island school teacher, a homemaker and mother, a bookkeeper, an actress.

Kates wants to debunk two myths about the homeless. One is that homelessness is solely the result of the misguided government effort to "deinstitutionalize" the mental hospitals; the other is that homeless people, especially homeless women, are eccentrics who actually prefer their rootless life styles. Certainly the wholesale dumping of chronic schizophrenics into the community accounts for many of the estimated 6,000 homeless women in New York alone. But as Kates makes clear, the problem is much more complex than that; it has been exacerbated by urban gentrification, which has drastically reduced housing for the poor, and by lethargic and confusing bureaucracies that practically guarantee that homelessness is a permanent condition. And while many of the homeless women Kates came to know were mentally ill before they hit the streets, others were not. They were just ordinary people living precariously close to the edge; one ill-timed stroke of bad luck did them in.

Phyllis Iannotta's murderer (and rapist, it turns out) was never caught. But by the time Kates returns to this story in the final chapter of the book, the fact seems almost beside the point. The real crime here is the presence of these vulnerable women on the streets in the first place, the real criminal a society that fails to provide decent asylum. Kates' compassionate account should be required reading for social policy makers currently deluding themselves with the myth that homelessness is a life style freely chosen.