A police cruiser drives down a dark Southeast street and stops. A teen-ager gets out and walks toward her front door.

"Awww, Jeannette. What you do?" someone shouts from across the street. "I know you did something wrong."

Jeannette Bennaugh, 17, is doing something right. She is among a group of youths from Southeast Washington streets asserting themselves as positive influences in a tough, urban environment.

She is a Law Enforcement Explorer, part of a branch of the Boy Scouts of America, volunteering with the Seventh District police.

At the expense of losing friends, she and the other 30 Explorers try to be the good guys. It's cost them; some of their former friends call them "snitchers."

"A lot of my friends don't trust me anymore," 17-year-old Shawn Turner puts it simply. An inspector and the highest ranking of the group, Turner intends to be a police officer.

Not all do. Kecia Cooper, 15 plans to be a lawyer. "We're trying to fight crime," she says, "but most of the people around here (far Southeast) are trying to make crime.

"Our community is all messed up because you got adults pushing drugs on kids and kids stealing and stuff to buy the drugs, then acting crazy once they get it."

Explorer adviser and D.C. Police Officer Frank Copeland understands the pressures confronting them. He says they are extraordinary young people with excellent potential. "You've got to have dedicated people with leadership qualities," he said, "people dedicated to the cause."

The cause is character development, crime prevention, the war against drug abuse, alcoholism and apathy in the black community.

Explorers wear uniforms similar to those worn by District police officers. They distribute crime-prevention literature: learn and teach crime prevention techniques, and go on field trips. They ride in police cruisers to learn the details of police work, help the elderly and clean up neighborhoods.

Isaac Braxton, 16, who's been an Explorer three years and is a captain, says being an Explorer gives his life special meaning.

"I'm setting an example for the other kids who're coming up, who're about our ages now," he says. "Instead of being out on the street getting into trouble, I'm trying to show them how to do what's right."

Explorers, who range from 14 to 20 years old, meet twice a week for planning and drill practice. They also function as a support group for each other.

Most are students at Douglass and Hart junior high schools and Anacostia High School. Two attend Notre Dame and St. Cecilia Catholic high schools.

"We've been around crime all our lives," 16-years-old Jesse Porter says, "robberies, drug deals, fights, weapons drawn, all kinds of stuff."

Thomas Bartley, 16 adds "You can always sit in your house and ignore it, but we decided to try to do somethng about it."

They try to convert their friends too, with admittedly less success than they'd like. But they've had some; the group keep growing.

Officer Copeland started the Seventh District's Explorer post after Third District police established one in 1976 to replace the defunct police cadet program.

An energetic 36-year-old, Copeland serves many roles from counselor, mentor and pastor to friend and father.

"The majority of the group are from broken homes and they're at the age when most young people begin to get into all kinds of things. I try to give them something constructive to do," he says.

They have an intense interest in fighting drug abuse, and recently put on a play about the life and death of a teen-age junkie on the corner of Martin Luther King Avenue and Talbert Street SE.

"It took a lot of courage for the Explorers to take over that corner and give the demonstration," Copeland said.

It's called "Heroin Corner" because thousands of dollars in dope is sold there everyday, he explained.

Every week the group learns more about law enforcement through psychodramas performed under Copeland's direction in a police station classroom.

"If you approach people with compassion and make them look at themselves, tells them, "you can prevent crime."

Cooper can testify to that. She says she once saw a friend going into a woman's pocketbook. She asked him quietly, "Why would you want to take what's not yours? Suppose it was your mother's, you wouldn't want anyone to rob her."

"You're right, Kecia," the friend said. "You're right." He left the pocketbook untouched. CAPTION: Picture 1, Explorers Jeannette Bennaugh and Shawan Turner, both 17, listen to account of domestic spat. By Joel Richardson -- The Washinton Post.;

Picture 2, Officer Copeland explains radio procedure.; Picture 3, Adviser Frank Copeland admjinisters oath to Explorer post.; Picture 4, Copeland and Explorer Shawn Turner leave for patrol, Photos by Vanessa Barnes HILLIAN -- the Washington Post