Susan Heeger had lived in Manhattan for only a month. Long before she had moved here, though, she had learned the lore of big-city America. She knew those stories about the criminals and the creeps, and she knew the story about the crowd that gathers and watches indifferently while the criminals and the creeps do their dirty work.

Like most of us, Heeger, who just turned 25, had never had much contact with the law. The policemen she had seen cruising the streets of her neighborhood - the East 20s - had made her feel more comfortable living alone in the big city. She still had been afraid, of course, but the ubiquitous bright blue police cars had made her feel a little safer.

Heeger goes to the movies a lot. This Monday night, July 10, she and a friend had been to see "The Last Waltz" on the West Side. Her friend rode part of the way home with her on the subway and Heeger went on alone across town and down the Lexington Avenue IRT to its stop on Park Avenue and 28th Street, which is about four blocks from where she lived. It was a warm, muggy night. Heeger carried an umbrella, because there had been a chance of rain, but it was not raining as she emerged from the underground station and started east on 28th.

The street was very dark. She passed a beatup old car and heard loud, querulous voices. The voices frightened her, and she began to run toward the streetlights at the next corner, 28th and Lexington. As she ran, she heard a man's voice come from the direction of the car: "That's right. Keep running, keep running." When she reached the corner, she noticed to her horror that the car had followed her.

Heeger and several witnesses have described in sworn depositions what happened next:

A woman who describes herself as a designer and part-time waitress was out walking her dog at the time - about 12:30 a.m. on July 11 now - and saw Susan Heeger reach the corner diagonally across the intersection from her. The woman said she noticed Heeger because she reminded her of a friend of hers, and added, "Immediately after I saw her, I saw an American car screech to a halt near her and a man in a T-shirt jump out and grab Heeger by her hair. He flung her to the sidewalk by her hair and kneeled down with his knee in her stomach. Heeger started screaming hysterically for help and for someone to call the police."

The woman said that at first she thought the man was Heeger's boy friend because there was something intimate about the way he was handling her. Another witness, who arrived a moment later, said he had first thought Heeger was having a bad drug trip, and that the man on top of her was a member of her family trying to subdue her.

The woman with the dog said the man began to drag Heeger by the hair across the intersection, stopping from time to time and kneeling on her stomach. The woman said she ran toward the man and screamed at him to let Heeger go, but that he ignored her.

"I considered kicking him and attacking him to cause him to let her go," she said, "but he was too big and intimidating. I remember being astonished at how long he was taking to drag her to the car."

Another witness, who was asleep in a room which overlooks the corner, said he was awakened by Heeger's screaming and looked out his window. "The man seemed to be ripping at her blouse as she was screaming and people were gathering. The woman was on the ground quite sometime. During part of this time, she was on her back with her feet in the air."

Heeger said later that she thought she was being kidnapped. When the crowd began to gather, she begged for someone to call the police. "Please help me, I don't want to get in that car," she said. The man kept telling her to shut up, but he did not say anything else to her at first, Heeger said.

Then the man handcuffed her. Even then, Heeger said later, "It did not cross my mind that this man was a policeman."

Susan Heeger had moved to New York from Charlottesville, Va., a peaceful university town. Three years ago, after graduating from Harvard, she had gone to Charlottesville to study fiction writing at the University of Virginia, and the next year she was asked to teach writing there. It was a good place for her to write - in three years she finished a novel and several short stories, two of which were published in literary magazines - but she had decided that it was time to live somewhere new. She had a lot of friends living in Manhattan, so it seemed a logical place for her to move.

She found a part-time job in the college books division of St. Martin's Press, which gave her enough to live on and time in the mornings to write. She found an apartment on a nice street, and she was seeing a lot more of a man she had been dating for about a year. She was settling happily into a new life.

And then, according to witnesses and documents filed in court, officer Frank D. Costantino, a plain-clothes policeman from the midtown south precinct of the New York City Police Department, knocked her down in an intersection and apparently attempted to arrest her for loitering for the purpose of prostitution.

A large crowd was gathering at the corner of East 28th and Lexington, and another plain-clothes officer got out of the battered car and told them, "She's a psycho. Come on, I'm police officer, we've chased her twice tonight." He flashed a police badge and other identification, but Heeger Kept yelling, "I don't believe you."

Officer Costantino also told the crowd, "I've been chasing her for six blocks now." To Heeger, he said, "Look at my face. Don't you recognize me?"

"Why should I recognize you?" Heeger said. "I don't have any reason to recognize you."

The woman with the dog said that she, too, was crying hysterically by this time. "Someone in a nearby apartment threw a bottle out of a window which crashed on the ground right near me."

A man in the crowd began repeating the license number on the battered car, to memorize it, and so the police officers could hear that he was taking it.

At one point, Costantino began to rummage through Heeger's purse. Someone in the crowd screamed, "You have no right to search her purse."

Finally, a marked police car arrived and uniformed officers got out. One witness said they began to shove people in the crowd and said, "Break it up, it's all over." The uniformed officers told the crowd that the plain-clothes officers were making an arrest.

Costantino tried to put Heeger in the back of the beat-up car, but there were already six women squeezed in there, sitting on each other's laps. One said to Heeger, "He pulled my hair, too." The women would not let Heeger in, so Costantino put her in front, between him and the other plain-clothes officer.

"Why were you screaming?" Costantino asked.

"I thought you were going to kill me ," Heeger replied.

"Oh yeah, in your line of work?" Costantino taunted.

Heeger said later that she felt at that moment as though her identity were slipping away from her. She began to babble, she said. "I went to Harvard. I'm a teacher.A writer. I work st St. Martin's Press." He did not respond, she said.

Costantino drove to the midtown south precinct. A uniformed officer approached the car and said, "What are we going to do with all these c - ?" The other women were made to get out of the car and into line, but Costantino told Heeger to stay in the car.

Heeger said later, "First he said he was going to give me a break and let me go. But then his attitude changed. He started pleading with me not to get a lawyer and not to do anything about his 'mistake.' He apologized and asked me out for a meal or a drink. I refused. Finally he drove me home."

When they reached her apartment building, Costantino double parked and turned off the engine of the car. He said he didn't want to leave her so upset, and he asked again if could buy her a drink. When she refused, he said, "I don't know what you feel you need to do about this." She asked him for his name and badge number, which she wrote down on a scrap of paper. "I don't know what I'm going to do," she said before she got out of the car.

After she was alone in her apartment, she began to cry again, she said in an interview. She thought she was getting hysterical, so she called a friend, who arrived a few minutes later with a bottle of Drambuie. Heeger said her friend put her in a warm tub and washed her off. She was scraped and her scalp hurt where her hair had been pulled. Her neck was wrenched. She drank some warm milk with Drambuie in it. Her friend held her and talked to her, and it was a long time before she stopped crying.

The next day, Heeger talked to her family - her parents, who are divorced, live in Northern California - and her friends about what had happened to her. "I was afraid that I would be a double victim," she said, "that in addition to being battered and falsely accused, people would think that I was a prostitute just because the police picked me up.

"I finally decided it was too important to me and other women to let it go. The police should be protecting our freedom to be in public without fear of being molested, rather than themselves molesting us."

Heeger went to the New York Civil Liberties Union, where she discovered that there was a case similar to hers already pending in the courts. A 41-year-old church worker named Arlene Carmen had been arrested on Jan. 7 of this year in a police sweep of prostitutes. Carmen had been on the street talking to prostitutes as part of a church mission to get them better health care. She was booked for loitering for the purpose of prostitution and was held in various lockups for 22 hours before she was freed under an NYCLU-obtained writ of habeas corpus. Carmen sued for $150,000, and asked that the loitering for prostitution law be declared unconstitutional.

After Heeger told her story to Richard Emery, the NYCLU lawyer representing Carmen, he agreed to take the case. On July 26, Heeger filed suit against Costantino, and state and city officials, for $300,000.

Frank D. Costantino works in the prostitution control unit of the midtown south precinct. He is 33, married and has been on the force for 10 years. There is an internal police investigation underway of the allegations in Heeger's suit, but no action has been taken against Costantino, who is still working on the street.

A police department spokesman gave this explanation of Costantino's actions: "One of the 'ladies' in the car pointed her (Heeger) out as being a possible perpetrator of a crime against her in court the previous day." Beyond that, the police department would say nothing about Costantino or the suit against him.

In a pre-trial deposition taken by Emery last weeK, Costantino admitted that he had grabbed Heeger by the hair, but said that he had identified himself immediately as a policeman. He said that he and the other officer working with him, Joseph Buffolino, never suspected Heeger of being a prostitute. He agreed with the police department statement that he had stopped Heeger on the basis of an allegation against her by a woman in the car whom he did not know and had just arrested.

Costantino said that the woman in the car immediately called out to him that Heeger was not the right woman, but that he had continued to hold Heeger because he suspected her of having something in her purse.

The other women in the car all were booked for prostitution or loitering for the purpose of prostitution, Costantino said.

The police department said that Costantino was not permitted to comment publicly on the case.

East 28th, between Park and Second Avenue - the four blocks Heeger had to walk - is not a mean street. There are a few trees, and a tiny park between Third and Second. The buildings are not so tall that the sky is merely a thin strip far overhead, and at the corner of Third and 28th the view uptown is dominated by the Chrysler Building, which is magnificent in the distance.

It is one of those streets where people live and work, so that it is possible to have several restaurants, a hardware store, a Chinese laundry and a funeral home within a block of your apartment. Along these four blocks are also an Episcopal church; one of New York's beautifully restored, 19th-century firehouses; and a hair stylist ("We sell and service men's hair").

At night, commerce moves from the buildings to the sidewalks, just as it does on so many of Washington's prosperous streets. Prostitution is not very pretty, but it is inevitable and difficult to stop, and unless it interferes with other forms of business, not much is done about it. When it was thought to be hurting ticket sales for Broadway shows, and theater owner and restaurateurs made a fuss, police cracked down. And when the 1976 Democratic National Convention was scheduled for Madison Square Garden, something had to be done to keep the prostitutes out of midtown, where the delegates would be staying in hotels and eating in restaurants.

So the state legislature passed the loitering for the purpose of prostitution law, which made it easier for the police to get the prostitutes off the streets. It went into effect on July 11, 1976, one day before the convention began, and two years to the day before Heeger was taken into custody by officer Costantino.

One of the ugly questions that comes up in a case like Heeger's is how difficult it would be for the police to mistake her for a prostitute. It is an insidious question which puts the victim on the defensive, like some of the ugly questions that are raised in rape cases. Was it easy to mistake Heeger for a prostitute? Was it easy to mistake Arlene Carmen, the church worker, for a prostitute? What does a prostitute look like, anyway? Did the Jane Fonda character in "Klute" look like a prostitute?

Richard Emery, Heeger's NYCLU lawyer, said, "As long as this law is on the books, women walking the streets of New York are in real danger from the police. The law allows the police to arrest a woman if an officer suspects her of being a prostitute, even if her actions are entirely innocent." Emery said the NYCLU believes a loitering-for-the-purpose-of-prostitution law is so vague that it is unconstitutional, although its constitutionality has been upheld in one case as far as the New York State Court of Appeals.

The problem with the law, according to Emery, is the phrase "for the purpose of prostitution." Police guidelines for implementing the law say an arrest can be made if the person suspected of being a prostitute beckons or speaks to other people twice in a public place where prostitutes are known to work.

Emery said a law which gives so much discretion to the police encourages abuses. He thinks Heeger's case "shows that it is likely that other innocent women have been arrested and not come forward" because of police intimidation or fear that some people would suspect them of being prostitutes.

In his deposition, Costantino said that men are never arrested under the law, and that the arrests had not seemed to curb prostitution.

Heeger's suit, for which no hearing date has been set, asks for payment of damages and, as part of a class action, asks that the law be overturned. The second part of her case is weakened because she was not booked, Emery said. But he thinks it obvious that she was picked up as part of a police sweep under the law because the other women in the car were booked on prostitution charges and because Costantino is part of a prostitution control unit. Emery thinks she has a strong case for damages. "She feels the need for revenge. They really harmed her. They treated her like s. . . ."

Her telephone number was available from information, and before she could get it unlisted, the creeps began to call. One said he had seen her picture in the Voice and had been masturbating over it all day. She was afraid that they could get her address from information, too, so she went to stay with a friend and has not spent a night at her apartment since. Next month she and her friend are moving into a new apartment together.

After a few days, letters began to trickle into St. Martin's Press. Some were from friends, and were reassuring, but others were not so reassuring. Even letters of support sometimes ended ambiguously. An assistant D.A. in another borough of the city began, "As someone charged with the responsibility to enforce this medieval law, I would just like to express my personal support for your efforts." At the end, he gave her his phone number and asked her to call him.

She is hanging on to the letters in case some day she wants to write about what happened to her.

Her story went out over one of the wire services, and calls have come in from newspapers around the country. One paper in Charlottesville ran a story which mistakenly said that she had been wearing black hot pants when Costantino arrested her. She thinks perhaps she had said black cotton pants and the reporter had misunderstood. (The paper later did run a correction.)

People magazine also wanted to do a story. They said it would take two hours for them to interview her and take her picture. It ended up taking 10 1/2 hours. They photographed her in her apartment, at her office and twice on the corner of 28th and Lexington, in the daytime and at night, after asking her to put on the same clothes she had been wearing on July 11. She said that it had not been pleasant to stand there in those clothes and have people watch her as the camera clicked away endlessly. She vowed not to go back there again.

After she had been out on the corner for awhile during the night photo session, and was near the end of her patience, a man had approached her. "Are you the one the cops beat up?" he asked expectantly. "No," she lied. She said that he had known she was lying, and she could see the hurt in his eyes. That still bothers her.

And now People magazine has decided that it probably will not run the story.

Heeger doesn't blame the NYCLU for what she had been through since she and they went public with her case. But she has had enough.

Susan Heeger and I first met three years ago. We had both just moved to Charlottesville to study under the same writer, and through him we became friends. She and I used to read and criticize each other's work, and because my wife and I liked going to the movies as much as she did, the three of us often did that together.

After our interview last week, I talked to her on the phone. The last thing she said to me was, "Please don't make me look bad."

Before July 11, and all that's happened since, she would not have said that.