Delores Massey stood under the street lamp at l4th and N streets NW Friday night, wearing Oleg Cassini jeans and glossy lipstick, waiting for a man to solicit sex so that she could arrest him.

Massey, a five-year veteran of the D.C. Police Department, was posing as a prostitute as part of a crackdown on sex for sale, which law-enforcement officials say has proliferated into a violent, multimillion-dollar-a-year industry.

Because of increases in such sex-oriented businesses such as massage parlors, escort services and modeling agencies, as well as street prostitution, Police Chief Maurice T. Turner Jr. recently ordered the department's prostitution and obscenity squad moved from the 3rd District, where the unit which had covered Washington's notorious 14th Street strip for the past five years, to headquarters downtown.

Operating from the main police headquarters, the squad will have the authority to fan out throughout the city.

"We're talking about 40 restaurants that cater to nude dancers, and countless private homes being rented out as 'trick pads,' " said morals division Inspector Kris Coligan. "Hotel and motel managers, from the small tourist home in Northeast to the fancy guest house in Northwest, are complaining of infiltration by prostitutes and their pimps. The bottom line, however, is that 95 percent of this starts on the street, so the street action will be our priority."

"And we're vigorously going after 'johns,' " Coligan added, using the street term for men who pay for sex.

Since October, when the unit moved downtown, the 21-member prostitution squad, which includes an undisclosed number of undercover women, has arrested 133 adults and five juveniles on charges of prostitution and pandering.

Police estimate that there are about 500 prostitutes working the streets and hotels of Washington in shifts. It is a 24-hour business where girls earn from $300 to $500 a night, police said.

Although law enforcement officials periodically crack down on prostitutes working the corners along 14th Street, police sources say that this latest effort is aimed at hitting the sex business so hard that Washington will no longer be a desirable location for prostitutes and pimps traveling through major cities from New York to Miami.

"We have identified a need for enforcement," said Lt. Robert A. Poggi, commander of the the prostitution and obscenity unit. "This is a natural outgrowth of citizens' support. We respond to that support. When we hear the community say, 'Go get 'em,' we work overtime.

"There are a lot of misconceptions about prostitution being a 'victimless' crime," Poggi said. "There is a tremendous amount of violence between johns and prostitutes. It's not uncommon for a group of them to snatch a girl, beat her, rape and rob her. A lot of these girls are runaways who can't go the police."

Two weeks ago, D.C. police arrested a 14-year-old girl who had been standing on a corner at 14th and K streets NW wearing nothing but a thin pullover dress. She told police that she had just had a date with a local doctor who, after paying for sex, advised her that she had bronchitis.

"When her mother came in to get her, she just looked at her and said matter-of-factly, 'Have you been trickin' again?' " Poggi recalled.

Delores Massey is just one of several undercover policewomen who step squarely into the street life, on the front line in this effort to curb prostititution.

"A lot of these guys just feel inadequate," Massey said during an interview Friday night as she waited under the street lamp, hands on hips. Cars passed slowly, the drivers sometimes uttering compliments and obscenities.

"Some of them are educated and have a lot to say to a woman, but they can't get it to amount to anything," Massey said. "All I'm interested in hearing is what it takes to make an arrest."