At the heart of the recent increase in drug arrests among D.C. public school students is an undercover squad of baby-faced rookie police officers who are taught that to succeed in their work they must fail tests, skip classes and buy drugs from their schoolmates.

"The biggest problem in training the officers is to get them to realize that the drugs are out there and all they have to do is buy them," said D.C. police Detective Bill Larman, a former undercover vice officer. "And that is what always surprises them the most. They can't believe how easy it is to buy drugs in the schools."

Larman and Detective Jim Edwards are in charge of training rookie police officers to pose credibly as high school seniors. The officers' work has resulted in the arrest of 19 students on drug charges in the past four months, including six arrests yesterday at Anacostia High School.

The police department's "school squad" has been around for at least 20 years, but it is only in the last year that the unit has conducted intensive training for its undercover officers that produced a sharp increase in the number of arrests of high school students.

D.C. School Superintendent Floretta D. McKenzie told a congressional subcommittee this week that drugs are a "formidable" and "discouraging" problem in the schools and that the number of young people selling drugs may be on the rise.

Larman said that every high school in the city has a drug problem and undercover officers have been able to buy PCP, cocaine and marijuana at the schools.

"Whatever is on the streets is in the school, with the exception of heroin," he said. "And that is probably there as well. We just haven't been able to buy any heroin yet."

Larman said that the amount of cocaine sold in a packet is reduced to bring the price down from the usual $50 to an affordable $10 for high school students. The purity of the cocaine bought by his officers was as high as what is normally sold on the busy street markets of Washington, Larman said.

"Just because it's kids selling to kids, it's not garbage stuff," he said.

For security reasons, police officials are unwilling to say exactly how many officers are passing for students at local high schools, although there are indications that there may be as many as a half dozen. Edwards said that the squad members are all volunteers mostly gathered from graduating classes at the police academy.

"Some are from the District," he said. "We just have to be careful not to put them back into a school where they are known. Sometimes they run into a former teacher who has transferred and then we have to move them to another school."

Edwards and Larman stressed that they teach the officers to act in as normal a manner as possible, but the play-acting sometimes produces unexpected results.

"We caught some of them trying to be good students," Larman said. "They were falling back into their old study habits and working to be grade A students. We had to tell them that by normal, we meant that they not study so hard, that they get C and D grades and skip classes."

Edwards said that they teach the officers all about drugs and how the drug business operates.

"What we can't teach them is what a drug dealer looks like," he said. "There is no profile of the high school drug seller. They can be black, white or Oriental and income doesn't make any difference. They can be first, second or third born. Some of them will end up losing college scholarships because of their drug dealing."

Larman said that the undercover work for the young officers creates a "split personality." They look, act and dress like students, he said, "but we constantly remind them that they are police officers, so they don't forget who they are and what their objectives are."

To help them balance their dual roles, Edwards said, each officer is expected to report in by phone or in person every day.

"They keep extensive records of their contacts with the drug dealers," he said. "There is a daily log of the contacts they have made and the drugs they have bought."

Larman said that the carefully documented drug transactions become part of the evidence submitted in court.

"What we have is a one-on-one situation," he said. "It is the officer's word against the drug dealer's word. But with our documentation, we can make it 2 to 1 in favor of the government."

Earlier this week, six high school students, including four from McKinley High School in Northeast and two from Anacostia High in Southeast, were indicted by a federal grand jury on drug selling charges stemming from undercover work. A seventh student who attends Roosevelt High School was indicted April 1 on drug selling charges.

All seven were charged with two to seven counts of selling drugs within 1,000 feet of a school, under a recently passed federal statute with penalties of up to 30 years in prison and a $250,000 fine for each count.

U.S. Attorney Joseph E. diGenova praised police Officer James Simpson, who was assigned to McKinley, and Arthur Brooks Jr., who was assigned to Roosevelt.

Larman said that some high school students turn to selling drugs because of peer pressure or to emulate students whom they admire, while others do it simply to make money.

Larman said that selling drugs is easier for some students than putting the effort into their school work. He said it becomes a profitable business and sometimes a student's family benefits from the added income.

"We are thinking about going after the assets of the family," he said. "If they buy things with the money made on drugs, we can confiscate them," he said. "It wouldn't be difficult to prove that some families cannot afford the expensive items in their homes."