The identity of Susan Noelle Cvengros's killer is almost as much of a mystery as she was.

Some friends described Cvengros as shy and quiet, yet she worked as an exotic dancer. She was fiercely independent, they said, but she would not drive and relied on friends and strangers for transportation. She would tell friends that she was close to her mother and brother, but she never gave details about her family.

Cvengros, 24, a small-town South Carolina girl who moved to the big city with aspirations to become an artist, died a horrendous death a little more than a week ago. A former roommate found Cvengros dead about 5 p.m. May 21 in the bedroom of her basement apartment at 416 F St. NE.

Police said Cvengros was partially clothed and sprawled across a bed. Her throat had been cut from ear to ear, and she had been stabbed several times. Her pet rat and ferret were still caged. Her cat was in the front yard.

No one appeared to have forced his way in, police said. Officers found paraphernalia used with heroin in the apartment.

Police have made no arrests. Investigators have talked to several of Cvengros's acquaintances and are trying to find out what she did and whom she talked with on the day she died. They are trying to put together details of her life but have found that her friends didn't know much about her.

Authorities said it appears that Cvengros spent her last night at home.

"She was so sweet and friendly, but she never talked much about herself," said a dancer at JP's Nightclub on Wisconsin Avenue NW, where Cvengros worked for a year. "That's really unusual at a place like this because most people open up quite a bit about themselves." Like several of the employees at the nightclub, this women did not want her name used because the killer is at large.

According to friends of Cvengros and public records, from 1995 to 1998, she lived in Columbia, S.C., near where she was raised; McKeesport, Pa., where her grandmother lives; and then Baltimore, where she lived in at least two locations before she moved to Washington about 18 months ago.

Ed Chase said he evicted Cvengros from his Baltimore apartment house in September 1996 for four months' failure to pay rent. When Cvengros arrived in August of 1996, she seemed bright and well-spoken, Chase said, but she appeared to deteriorate, and "the day we threw her out . . . it's like she didn't realize what was going on."

Shortly after moving here, Cvengros started working as a dancer at JP's. There, she specialized in routines that started with her wearing long, elegant gowns and dancing to the music of Enigma and other techno groups.

Early this year, she decided that she wanted to get out of exotic dancing, friends said. She quit JP's, where she made more than $500 a week, to work at America restaurant at Union Station, where she made $3 an hour, plus tips.

"She was trying to straighten out her life," said Michael Papanicolas, owner of JP's. She wanted to get a regular daytime job."

Joe Riescher, manager at America, said he met Cvengros when she came into the restaurant in January. Her application included the fact that she'd worked as a exotic dancer. She had more recently worked as a waitress at another restaurant and complained of being sexually harassed there, he said. He hired her in March.

"I intentionally didn't mention anything about her being an exotic dancer," Riescher said. "I ignored it because I wanted her to be able to make a new start."

She had been upset by a recent breakup with a boyfriend, friends said. She told one friend she was dating a doctor whose "uppity" family she had recently met. She also told people she was close to her mother and a younger brother, but she didn't discuss her visits home.

A woman reached by telephone in Pennsylvania who identified herself as Cvengros's mother declined to be interviewed.

Friends said Cvengros's family did not know she had worked as a dancer. One friend said Cvengros told her that she had come to Washington to attend art school and had met her latest roommate, an art school graduate, at the Corcoran Gallery. Cvengros's apartment held several of her works, including nature scenes and drawings of horses.

A man who frequents JP's and who befriended Cvengros shortly after she started working there said he spoke with her by telephone about 5:30 p.m. May 20, the day before her body was found.

"A man answered the phone, and there was a three- or four-minute pause," said the 46-year-old friend, who asked that his name not be used. "She came on the phone. She said she was sleeping, and she said, `I'll have to call you later.' She never did."

The man said that he "was interested" in Cvengros romantically but that she never responded. "There were others," he said. "She had a lot of friends." The man said Cvengros "liked to party," often visiting Tracks, Nation and other nightspots.

Riescher said he was surprised by the people who came to the restaurant to see Cvengros. "Some people you'd characterize as shady came in to pick her up," he said. Cvengros told him that a boyfriend from Massachusetts was planning to move to Washington and that the two of them were moving to an apartment on 15th Street NW.

Riescher, Papanicolas and others said Cvengros had complained that the lock on her apartment door was broken and that she was planning to move. A woman who had lived with her for several months recently moved because of concerns about their safety, Riescher said.

Riescher said Cvengros, who always showed up for work on time, was scheduled to work at 10 a.m. May 21. But she never arrived.

A report of an autopsy conducted May 22 showed that death resulted from "an incised wound of the neck, injuring the carotid artery and trachea, and stab wounds of the torso, injuring the lung." The manner of death is listed as homicide.

Authorities are awaiting the results of toxicology tests taken during the autopsy to determine whether Cvengros had used heroin.

While investigators search for Cvengros's killer, her friends are struggling to come to terms with her death. At JP's on Wednesday, her friends learned that she had been killed from a reporter. As of yesterday afternoon, detectives had not been there, her former co-workers said.

Riescher said Cvengros's death has deeply affected her co-workers at America restaurant.

"She had a lot of positive karma, and it messed up the chemistry of the whole restaurant when she was killed," he said. "Her nature was so positive. You knew she had been through a lot of hard knocks . . . but she hadn't gotten that hard D.C. edge yet."

CAPTION: Susan Noelle Cvengros, 24, was found dead last week in her Northeast Washington apartment.