DETROIT, SEPT. 1 -- In 1955, Rosa Parks made history. She was 42 then, vibrant and a little headstrong, which helps to explain why one December night she refused to leave a seat in the "whites only" section of a Montgomery, Ala., bus and move to the back of the vehicle, where Negroes were supposed to sit.

Parks, 81, is frail and in faltering health today. To the young, black man who entered her home Tuesday night, hit her repeatedly as she was sprawled on her bed and stole $53 from her, she was just another vulnerable old woman who lived alone.

But to those, black and white, who remember Parks's simple act of courage and defiance as the effective birth of the modern civil rights movement, the assault was both jarring and unfathomable, like someone's demented idea of a cruel joke.

Just before 1 p.m. today, Parks, slightly stooped and moving slowly, left her home on Wildemere Street here and rode in the back seat of an unmarked police car to downtown headquarters where Joseph N. Skipper, 28, was identified as the assailant of a neighbor woman. Dark bruises were visible on Parks's right chin and below her lip. The bruise under her left eye was hidden by tinted glasses.

"I'll cooperate, do anything I can," she said of her attempt to identify her attacker in a police lineup.

The assault on Parks has stunned this largely black city and much of the nation. Messages of concern have poured in from the White House, state and local officials and ordinary citizens. But as the immediate shock began to fade, it was also noted here that, except for the notoriety of the victim, this kind of crime is all too common in the nation's inner cities, where drug addicts and street thugs prey on the old and the weak.

Bill Proctor, 46, a former federal law enforcement officer in Washington, was on Wildemere Street today with a cameraman from WXYZ-TV, where he now works as a reporter. "This is a city where these kind of things happen five, 10, 20 times a day," he said. "It is even more outrageous when senior citizens are the prey of these street thugs. It is the ultimate outrage to this city's black community and America's community to have this woman violated."

The block on Wildemere Street where Parks has lived since 1988 is a pleasant stretch of sturdy, two-story brick homes with neatly trimmed lawns. But the appearance is deceptive, for the block is an island of tranquillity in a sea of crime and violence. Nearby are the hulks of abandoned buildings, many of them the scars from the 1967 riots here from which parts of Detroit have never recovered.

The night before Parks was attacked, an 84-year-old woman who lives in a house directly behind hers was assaulted and robbed at home. Police said they will charge Skipper, a crack-cocaine addict, with that crime and another recent burglary in the neighborhood as well.

Gregory Reed, Parks's lawyer, said her decision to try to identify her attacker was simply the latest "part of her journey on this planet. . . . This is the modern-day Mrs. Parks."

Not much is known about Skipper, who police said will be arraigned Friday on charges of assault and robbery. He is a high school graduate with an arrest record and lived only a few blocks from Parks in a house with no water or electricity. Venus Crawford, 20, who lives across the street from the Parks house, speculated today that Skipper must have known his victim. "I just think he wanted to go in there and rob her because he knew she lived there alone," she said.

According to Detroit police officials, Skipper did not know it was Parks's house that he broke into, but once inside he recognized the frail old woman and said, "You're Rosa Parks, aren't you?" He demanded money, and when she produced $3 he slapped her and demanded more.

"He knew who she was, but he needed that crack," said one police official.

It is the gulf between the Montgomery of 1955 and the Detroit of 1994 that has so shaken those old enough to remember the gains and the price of the movement that Parks inspired. In a commentary on WGN-TV in Chicago on Wednesday night, Chicago Tribune columnist Clarence Page said: "How sad, how outrageous, that Rosa Parks has become a symbol of a political unity gained while social unity was lost. Perhaps her unconquerable spirit can now help us see just how much we have lost."

"She is the victim of what she fought to change," Proctor said. "It's sickening."

Parks told reporters here Wednesday that this was the first time in her life that she had been struck by a man. "I hate for anything like this to happen to anyone," she said. "Of course, in these times, none of us seem to be safe from this kind of treatment and violation."

Her assailant, Parks said, reeked of alcohol. He followed her to her upstairs bedroom. "He said, 'You're going to make me hurt you if you don't give it all to me,' " she recalled. "And then he started to pushing me around and hitting me."

Parks moved to Detroit in 1957 after her role in the burgeoning civil rights movement made it impossible for her to find work in Montgomery, and for the past 20 years she has lived in a city run by a black mayor. There is a boulevard named for her a few blocks from her west side home as well as a middle school.

When news of the attack spread through the city, there was a deep sense of anger. Skipper was apprehended by two young men who recognized him from a photo police had shown them. They roughed him up while waiting for police to arrive. One of them was arrested on embezzlement charges after being hailed on local television as a hero for having apprehended Skipper.

Today, Parks was in the process of moving to a high-rise apartment building with a 24-hour security detail to protect the tenants, who include former Detroit mayor Coleman A. Young. "I'm doing pretty good," she said. "I want to get back to my job."

Rosa Parks, above, who in 1955 made history by refusing to give up her seat in the "whites only" section of a bus in Alabama, shows bruises she suffered in an attack and robbery at her home in Detroit. Parks said, "I'll cooperate, do anything I can" to help identify her assailant, who police said was motivated by a need for crack cocaine.