First there was Mayor Marion Barry's "War on Heroin," Then there was "Operation Burbank," which had police sitting in none-too-inconspicuous vans and filming pushers and buyers. And now -- "Bamscam," the latest D.C. Police Department effort to cleanse the city's drug-infested corridors.

"Bam" is street talk for Preludin, a pill that can be used as either a substitute or booster for heroin. The scam involves police posing as sellers and arresting unsuspecting customers. Apparently, no other law enforcement officials in the country have used this tactic.

Bamscam is a variant of the old ploy of using policewomen as decoy hookers to try to eliminate sex-selling from what many consider a wide-open city.And, some law enforcement officials believe, it's likely to have the same results -- virtually none.

It marks a departure from the traditional undercover approach, in which police posed as buyers, then identified and often arrested pushers and methodically worked their way to the top of the drug-dealing ladder. In one instance, they uncovered the French Connection.

Police acknowledge that the new plan will nab very few big-time buyers. They aren't likely to cop a fix from some flat-footed stranger on 14th and T. What they will get instead are the occasional user, suburbanite "one-pillers" out for a weekend high, for instance.

The plan's supporters, say, however, that it should at least disrupt, confuse and scare off those kinds of buyers, and if it stirs things up even a little, they say, it's worth trying. Maybe so.

But others dissent, including some in the U.S. attorney's office.

When a narcotics detective walked into D.C. Superior Court two weeks ago with the first arrest, the assistant U.S. attorney handling the case decided that it should not be prosecuted. The drug sale -- one Dilaudid pill (a morphine-type drug) sold to an Alexandria man -- had been made by a police officer posing as a pusher.

Why bother with a one-piller, the presecutor felt; and, besides, it would be unlikely that a jury would convict someone who bought drugs from a cop.

The detective protested and was told by the prosecutor to "wait a minute, let me go check with somebody else," the detective recalls.

A higher level prosecutor also declined to press charges. The detective refused to back down. The matter was kicked up to U.S. Attorney Charles F.C. Ruff, who had approved the plan. Ruff overruled the other prosecutors.

"Whatever the views of individual assistant U.S. attorneys, it's both a legal and legitimate law-enforcement practice for disrupting drug traffic. The policy is mine, and I continue to support it," Ruff said later.

Still, some law enforcement officials question whether the new program is an effective use of police, prosecutors, courtrooms and judges.

"Experience tells you it's not going to work," said one official. "Even if it worked, it's a waste of resources. You don't want the Buyer; you want the pusher. This has been the thrust from time immemorial."

There are constitutional problems, too. A defense attorney for one of those charged with purchasing a narcotic from a police officer already has claimed entrapment and advised his client not to plead guilty.

But D.C. Police Inspector Kris Coligan, who proposed the idea, is determined to stick with it.

"I don't think any criticism of the program is fair," Coligan said last week. "I think it is needed to combat rising street trafficking in narcotics. Our personal contact with the community [shows] overwhelming support for it. They hope we get everybody."