SUMMER READING ISSUE : When the City Feared Sleep : CRIME : THE NIGHT STALKER: The Life and Crimes of Richard Ramirez,<i> By Philip Carlo (Kensington Books: $22.95; 421 pp.)</i>

During the summer of 1985, Richard Ramirez, a coke head and small-time burglar from El Paso with a Satan fetish, held Southern California in a state of anxiety that verged on open fear.

By the time he was captured, 13 people were dead, a handful of survivors were recovering from disfiguring wounds, either physical or psychological, and many people knew the lyrics to AC/DC’s “Highway to Hell.”

Philip Carlo’s absorbing, detailed account of the crimes and trial of Richard Ramirez returns us to the time when the city feared sleep. We follow the Night Stalker as he seeks his victims at the wheel of a stolen Toyota, with a head full of drugs and a pocket full of junk food that rotted his teeth and made it easier to identify him. And we watch him kill, so close-up that one almost feels like a voyeur.

But those interested in what motivated Ramirez’s blood lust may be disappointed. Carlo, an expert on child sexual abuse and cults, illuminates the dark topography of Ramirez’s psyche with a flashlight, not a beacon. We see an outcropping here, a depression there, but we never get a good look at the entire landscape.

Carlo does take us to the house on Ledo Street where Ramirez grew up, the youngest child of a stern railroad man. We learn that two of Ramirez’s brothers got into trouble with the law. And Carlo describes the rages that seized their father, Julian Tapia Ramirez. But these scenes are sketched in broad, TV-movie strokes.

As motivators for the pathology that drove Ramirez, we are offered three possibilities: As a child, Richard was kicked off the football team when he had a seizure; at 12, he witnessed a cousin shoot and kill his wife when she nagged him; and his mother, Mercedes, experienced difficult pregnancies that Carlo implies might have been somehow connected to nuclear testing 200 miles away in New Mexico.

None of these possibilities satisfactorily explains how a shy but likable enough boy could turn to crime, then graduate from petty burglary to become a dedicated serial killer who casually tortured victims, leaving some to live. Nor does it explain the Stalker’s occasional displays of humanity, as when he handcuffed a woman he had just ravaged to a bedpost but left the key so the woman’s daughter could release her when she came home.

Ramirez, who submitted to 100 hours of interviews with the author, is no help. He seems to have little insight into his own motives. In an almost comical revelation of the criminal mind working overtime to justify its view of itself as the victim, he is resentful that he was captured, not by the police, but by a crowd of ordinary citizens.

After identifying Ramirez as the suspect in the Stalker crimes, authorities released a picture of him that was displayed on the pages of newspapers and on the evening news. Flushed out, Ramirez tried to steal a car and run but was chased down and held by a group of working-class Latinos.

“My own people--can you believe it?” he asks his sister, according to Carlo. “Mexicans gave me up.” This is typical of his thinking. While sitting in jail, he developed a political perspective and rages against a system that punishes the poor. But his sociopolitical rants sound as superficial and unreflective as his Satan worship.

While he perfected a graveyard stare in court that attracted black-clad fans, many of them women who wrote letters pantingly wishing they could do such things as have sex with him while rolling in the blood of his victims, his grasp of the spiritual amounted to a simplistic belief that Satan would reward him in Hell if he did enough bad things.

But these gaps in our understanding of Ramirez may not be a bad thing. By not spending hundreds of pages trying to analyze Ramirez, Carlo allows the killer’s grotesque acts to remain squarely in view.

Because Carlo does so, a strange thing happens. Reading the book, I had the feeling I’d seen it all before. As the Night Stalker cruises the streets of Los Angeles, it’s easy to think of Ted Bundy looking for women with long dark hair parted in the middle. When he draws a pentagram on the wall, we think of Manson’s “Helter Skelter” homage to the Beatles.

When he cuts out the eyes of one victim, we are reminded of the desecrations of Edmund Kemper and Jeffrey Dahmer.

There are differences, of course. Unlike Bundy, the Stalker never bothered to try to snake-charm his victims. Shy and lost in his drug-induced frenzy, he struck from the shadows.

But is this a difference that matters?

Maybe the parade of serial killers of the last few decades are trying to tell us something: Our need to understand them is a one-sided exercise. Numbingly similar, their willingness to break the social contract that binds the rest of us can give us a vicarious thrill. But for an understanding of evil, perhaps we shouldn’t expect to learn very much from them.