The use of undercover agents and informants sometimes can be the only way to crack especially tough cases. The technique, however, also invites abuse. For both types of operatives, the incentive and ability to cut corners are always present. Reputations and rewards are improved when targets are found guilty, especially when the defendants are well known and the crimes are significant. But even in less important cases, undercover operatives are hard to control, because they operate on their own and report only what they want.

The Portland Press Herald/Maine Sunday Telegram series on undercover operations by the Maine Warden Service shed light on sting practices that rarely are aired outside a courtroom. Since the first exposé, additional Mainers have come forward with similar complaints: that they were tempted into illegal activities by an agent who provided them with abundant alcohol and who took the lead in hatching illegal plans.

Defendants assert that the agent was the primary lawbreaker in these episodes. Some say they pleaded guilty to avoid expensive litigation; some don’t deny their guilt. But for all, the question arises: Is this a fair way to conduct criminal investigations?

When I was a young lawyer with the U.S. House Judiciary Committee’s Subcommittee on Civil and Constitutional Rights, the panel decided to take a close look at how FBI sting operations were conducted.

Congress and the nation were still reeling from Abscam, the FBI sting that nabbed several members of Congress who accepted large amounts of cash from a “sheikh” who was actually an undercover FBI agent. None of the defendants was acquitted; “entrapment” is difficult to establish. Nor were they otherwise able to explain the payments.

But these men had not been suspected of corruption before, and the FBI took the initiative in tempting them. They may have been legally guilty, but is it fair to go after someone just because of his or her position? If so, anyone can be targeted for a sting.

The subcommittee wanted to know upon what evidence FBI stings were launched or targets chosen. Was supervision adequate? I spent an entire summer in a small room in the FBI building on Pennsylvania Avenue, filled to capacity with boxes of records and tapes from several closed cases. Subsequently, the subcommittee held hearings and questioned FBI and Justice Department officials charged with overseeing these operations.

What we found was that supervision was negligible and standards nonexistent. In one case, an FBI undercover agent was on the verge of arresting several Ohio judges for bribery. Then he accidentally learned that the bailiff who was telling him that bribes from the agent were being delivered to certain judges was actually stinging the agent: The “judges” were actually the bailiff’s buddies, playing the roles of judges for a cut of the “bribes.”

The agent who met with the supposed judges had never gone into the real judges’ courtrooms to see what they looked like, nor even looked at their photographs hanging in the courthouse hallway. The FBI supervisors relied on reports written by the agent alone, and backed up by taped conversations that the supervisors apparently never heard.

I read all the reports and listened to the tapes. Although hindsight is 20/20, I think it is fair to say that red flags were evident. The supposed judges did not sound like judges. The scheme was implausible. The transcripts did not match the tapes in several crucial respects.

But you had to listen closely. The agent undoubtedly expected to hear conspiratorial words, and so he did. And the supervisors trusted their well-trained agent.

As a result of the subcommittee’s review, the attorney general of the United States issued guidelines for FBI undercover operations that included standards for targeting and requirements of close monitoring. The guidelines were made public. When a new version was published several years ago, it, too, was made public.

If the country’s premier domestic investigative agency needs close monitoring, why should we assume otherwise for our state? Why are the Maine Warden Service’s guidelines not public?

Lawyers say that hard cases make bad law. Here, we have good cases in the sense that the defendants are not drug-dealing low-lifes, but our neighbors. We can identify with their plight. We should demand standards for undercover operations that protect all of us, not just the bad guys. That’s what good law is supposed to do.

Janice Cooper, of Yarmouth, is a Democratic state representative.