Despite warnings from another cop, the agents had swallowed an entirely fictitious tale concocted by informant Ronnie Bruce Edmond, 38. He is jailed now, awaiting sentencing next month on 17 counts of perjury, and still insisting his tip was an accurate one. After the kind of investigation that is supposed to come before a search, embarrassed federal officials paid $2.75 million to homeowner Donald Carlson, 44, who came out of the 1992 raid with one quarter of his lung capacity destroyed by federal bullets.

As the catastrophe showed, law enforcement’s most volatile weapons are criminals who turn to informing. An informant is as capable of setting up a cop he doesn’t like as he is of betraying a friend. The problem, as the defense in the Qubilah Shabazz case has loudly asserted, is that it’s a small step from being an agent to becoming a rogue agent provocateur Yet investigators are helpless without snitches, the only people who can open doors into criminal organizations. Properly controlled, informants are devastatingly effective. But they are not always properly controlled. In the past, much concern was focused on political cases – using informants and undercover agents to attack fringe political groups. Now, as the hunger for drug cases keeps on growing, the potential for mistakes and mischief is becoming a fact of criminal court life.

Cops don’t recruit snitches at church socials and PTA meetings. The vast majority of informants help authorities in order to get their own charge dropped or reduced. “Working off a beef,” it’s called. it’s the only escape from the “mandatory minimum” sentences Congress enacted in 1987 to toughen drug laws. Some informants begin that way, then develop a taste for the work and its financial rewards. A senior justice Department official estimates that there are thousands of professional snitches. Since 1987, the Drug Enforcement Administration and U.S. Customs Service – the federal government’s leading snitch employers – have doubled what they spend to pay informants: from $2 million to $31.7 million last year for DEA, and from $8.1 million to $16.5 million for Customs. Along the U.S.-Mexican border, a relatively low-level snitch can make $12,000 setting up a one-kilo heroin bust.

When an informant goes sour, bloodshed can follow. Last year the FBI prevailed on the Massachusetts Parole Board to spring a career criminal who was serving four to six years on his latest attempted murder and escape convictions. “The FBI was looking for Henry Marshall to work with them as an informant on a very high-profile, serious case,” says parole-board executive director Natalie Hardy. Three months after his January release, Marshall claimed he made initial contact with the FBI’s target, then got spooked, broke parole and fled to Washington state. On June 18 he robbed a tavern, killing owner Dennis Griswold. “I know a little bit about how this works,” says the victim’s daughter, Danielle, a Tacoma police officer who often uses snitches in street drug busts. “An FBI agent told me, “We never thought this would happen.’ Then he tells me, “We were close on his tail.’ I’m like, “Bulls–t’.”

Law-enforcement officials insist that agencies know how to prevent snitches from abusing the system. “There’s a tremendous amount of supervision that goes into management of informants,” says DEA spokesman Frank Shults. Technology helps too. Videotape and audio bugs record the activity of snitches – and give defendants less room to plead entrapment. But relying on a population of drug dealers, felons and other lowlifes for aid and comfort is always going to be a risky business for cops, snitches – and innocent bystanders.