Her name is Sandy Austin and she's a District police officer. She's 23 years old, five feet, three inches tall, maybe 115 pounds with her snub-nosed service revolver. She's also a lesbian.

"I've always been an up-front person," says Austin, who says she has been homosexual since she was 16."If people asked me if I was gay I would tell them. I am what I am. But the bad thing about being gay in the department is that you can't really be yourself. You always have a weight to carry."

As one of 340 women on a force of 4,000 officers, Austin has had to fight for her reputation as a tough, effective cop in a traditionally macho job with a "tough guy" image.

She is the first acknowledged lesbian on the force, and has had to contend with what she considers the fears and suspicions of fellow officers who do not know and cannot understand and of people who unfairly stereotype lesbians as hefty, bull-like women in denim jackets and army boots.

"Sometimes you feel really alone," she says.

Last week, Austin, decided she had to set the record straight. She screamed discrimination and filed a complaint with the department's equal employment opportunity offices. Austin claimed she had been removed from her five-month-old detail as an undercover officer with the Seventh District's vice squad because she is gay.

She had been working her usual evening tour she recalls, and was ready to hit the streets. But Lt. George Wesley, one of her supervisors called her into his office. Wesley told her she was being relieved of her undercover assignment and would be returned to uniform work, despite 15 months of good work on the vice squad, Austin said in her written complaint.

No reasons were given.

"I could't understand why this was happening," Austin said the other day. "Hadn't it been only about 15 minutes earlier that I received a PD7551 [a letter of commendation for exemplary service] . . .? Then it hit me, this sudden turn of events could only have come about because they had found out I was gay.

"After all, this was the D.C. Metropolitan Police Department, and no one was allowed to have a private life, especially females -- and especially if it was different from everyone else."

One week later -- and several hours after a Washington Post reporter began making inquiries about her complaint -- police officials reinstated Austin.

At that time, Austin's commanding officer, Deputy Chief James Kelly told a reporter that he and Assistant Chief Maurice Turner had returned Austin to her old detail to "keep down any bad press." But the department's reason for relieving Austin of her undercover duties remains a mystery, and Kelly did not return several telephone calls placed by a reporter yesterday.

Turner said yesterday that "the department measures job performance and not sexual preference. . . . We don't compile any statistics or keep a file of people who are gay."

Under the District's human rights laws, it is illegal to discriminate against city employes on the basis of sexual preference.

For Sandy Austin, the issue doesn't die with reinstatement. She says she's been marked, officially and publically.

"From now on, every step I take is going to be carefully monitored," she said. "There're going to get on my back and try and get me upset and watch for me to make a mistake so they can come down on me. I love my job, but I don't know if it will be good for me to go back to vice or not. I just don't know."

Austin, was born in Clarksburg, W.Va., the fourth of ten children. She moved with her family to the District when she was eight, but when her mother died three years later she went to live with an older sister, Cherry Earl.

"She was 16 when she first came to me and told me she was gay," says Earl, who is director of communications for the National Association of Community Health Centers.

"She was a good, active student at Coolidge High School, and I was really shocked at first. I thought it was my fault . . . But we had a lot of serious talks about it. She had had boyfriends and went out with fellas, and I'm sure she gave it all a try. But she was a very serious-minded young woman and that is what she chose. It's her, and it wasn't going to change."

After she was graduated from high school in June, 1974, Austin went to work as a police cadet in the communications section of the police department. Three years later she enrolled in the police academy, and graduated in June, 1977.

During her first year, she walked a foot patrol on Martin Luther King Avenue SE. The whole time, she says she was "thinking of ways to get myself to the vice squad. That's where the real police work was being done."

But while Austin proved at home on the streets, it was in the police station that she had problems.

"When I first came on the force a lot of the guys, because they wanted to go to bed with me, wanted to know about my private life. They'd ask who my boyfriend was and I'd just make up a name," she says. "It's like I'd get up in the morning and decide who my boyfriend would be that day.

"I had a fake diamond engagement ring that I wore for a while, and pictures of 'boyfriends' in my wallet. I had places made up that I'd been and things that I'd done."

Austin says there are others like her in the department, but they are afraid to acknowledge that they are gay. She says, "they don't want people to know because they are afraid they'll lose their jobs and their friends."

"I'm not trying to be a hero or an example," she maintains. "I'm a good cop and I want to work in vice. I don't want special treatment -- and I sure don't want any raw deals. I just want to go about my job."