"Let's all give yourselves a big hand for coming out here today," said Mayor Marion Barry at the 7th District's 3 p.m. roll call last Thursday.

The applause of Police Chief Maurice Turner and the mayor nearly drowned out the halfhearted claps coming from the roomful of officers. About 100 of them had listened to Barry discuss their contract, their feelings and concern with area unemployment. Then a sea of blue shirts swept out of the room, the faces above them bored or angry.

"It's a good thing I didn't say anything," muttered William H. Vaughan III to his steady partner, Stanley Hardesty, as they climbed into scout car 187. Vaughan, a 10-year veteran and master patrolman, and Hardesty, with 13 years on the force, had been riding together for almost two years. Like every other officer willing to discuss it, they were angry about their controversial new contract.

But as they settled in for their night's work, there was little talk of personal matters.

This night was to be dominated by the search for a dangerous man, an outpatient of St. Elizabeth's Hospital wanted for raping three nurses and assaulting a fourth. Yet there was still the daily routine: license plates to remember, domestic disputes, errant motorists to scold, alleys to watch.

The first call came at 4 p.m., a family disturbance. A woman said her husband stole her car. Nothing they could do, the officers said. Legally married, she had no restraining order against her husband.

Next came a sweep of the alleys, a search for stolen cars. "We have a habit of drilling tag numbers in each others' heads, tags we're looking for," said Vaughan of a diligence that has earned awards for both of them. "You'd be surprised at what you pick up."

As a master patrolman, Vaughan trains rookie policemen. He is a storehouse of faces and names. Hardesty, a former electronics technician, is the administrator, the tactician, "a genius," said his partner.

Almost immediately, they found a car, freshly stolen, stacked on cement blocks in a hidden lot. After filing a short report, they were back on the streets. Help an overdose victim on Atlantic Avenue SE, said the next call, but by the time they came, the woman had been revived. Her brother, who made the call for help, said she had had an epileptic seizure.

A juvenile disturbance was the next call. It could have meant anything from a loud radio to vandalism.

"Last night we had a call to come get a snake. I got a call for a bat in the house; we get it all. And one time," Vaughan said with laughter edging out of his throat, "I got a call from a lady, said she had a bear down the hall. I went. It was a raccoon."

They joke when they can, there being so little humor in what they have to do. Last Christmas, they locked up three men who shot a 16-year-old over a pair of designer jeans. A few months ago they tried to give CPR to a shooting victim and pieces of jaw, which they thought were dentures, came away in their hands. Like many officers, Vaughan says he is two people.

"When I get to work, my whole personality changes," said Vaughan, "but I try to come out with the attitude that these are my people to protect."

By 9 p.m., the calls were coming faster. At Newcombe Street SE, an 18-year-old girl has been sliced by her 40-year-old lover; on Third Street, a car window has been smashed after a scuffle. Between calls they search through alleys and parking lots for the rapist who, their sources say, is armed, erratic and proud of his recent crimes.

On Martin Luther King Jr. Avenue, they have a tip. They roll their car into an alley behind the Virginia and Norman Disco Nightclub. Backup officers arrive, some with shotguns. With guns drawn and flashlights out, the officers scan a garage, the roof and barred rear windows.

Hardesty saw a flash of white T-shirt and green pants -- what the suspect was last seen wearing. He yelled for the shadow to come out. It bobbed in the dark. The K-9 officer sent in a dog and out stumbled six frightened drunks with torn shirts and matted hair. One wore a ragged white T-shirt and green pants.

"We ain't nothing but winos, man," wailed one woman, as she stumbled down the steps.

"Damn, I really thought it was him," said Hardesty. Before he has time to consider his disappointment, they are on to another call. Family disturbance.

"This is what iritates me," said Hardesty, as they pulled into the parking lot on Livingston Street. "We should be out trying to catch that rapist and we've got to be telling some man, 'Now, don't you all fight . . ."

Before he could finish his sentence, a woman threw herself into the front seat of the car, pushing two infants into Hardesty's lap. Five more barefoot young children stood wide-eyed behind her as she shrieked and sobbed in the officer's arms.

"Oh my God, he's going to kill me, he's going to kill me, he's going to kill me," she screamed. Her hair was wet and she pulled a clammy towel around her. She was dyeing her hair, she said, when her boyfriend tried to choke her with a telephone cord. Then he had stormed out the house, "to get a gun."

Vaughan found the boyfriend hiding in the bushes down the street. He had no gun and was soon sobbing and muttering to himself. The woman thought of a place to stay for the night, gathered her things and took down phone numbers from Hardesty and Vaughan. She promised to seek court protection.

"Don't call unless you're willing to take the first step," said Vaughan, "unless you're serious about getting yourself together." Then they watched as the boyfriend crept back into the house, and the woman and her children left to stay with a relative.

It was close to midnight. The shift had ended an hour before.