TERROR IN OKLAHOMA CITY : Targeting the Radicals: A Quandary : Law enforcement: The agencies must be cautious about the rights of groups, individuals. They must also avoid playing into the extremists’ hands.

As his white-supremacist client sat on Arkansas’ Death Row, awaiting execution the night of April 19, defense attorney Jeff Rosenzweig heard the hatred from the heartland:

Scores of letters and postcards flowed to his law office in Little Rock, railing against the government and protesting the pending execution of Rosenzweig’s client, a double-murderer named Richard Wayne Snell.

“There were a number of communications of that vein,” Rosenzweig said, including one enclosed with a March, 1995, newsletter, Taking Aim, from a group called the Militia of Montana. The newsletter noted that on April 19, 1993, federal agents stormed the Branch Davidian compound in Waco, Tex., and it declared:

“April 19, 1995 . . . Richard Snell will be executed UNLESS WE ACT NOW!!!”

A representative of the Montana group on Saturday disavowed support for any lawbreaking. But with evidence emerging that those responsible for the Oklahoma City bombing were driven by an apocalyptic vision of confrontation with government authority and a desire to avenge the Branch Davidians who perished in Waco, law enforcement agencies across the United States face a quandary:

Must these groups be targeted more rigorously by police? If so, how can that be done without trampling the civil rights of groups and individuals? And, as in the case of Taking Aim, which linked the Waco confrontation with a call to action, at what point does constitutionally protected, yet inflammatory, rhetoric end and illegal incitement of violence begin?

The question, while suddenly new for Americans, is one that other Western democracies successfully have faced in the last generation. In the 1970s, for example, both Italy and Germany faced murderous domestic terrorist organizations--the Red Brigades and the Baader-Meinhof Gang.

Both countries succeeded in combatting the terrorists by the early 1980s. Although both countries took some actions that angered civil libertarians, they largely respected civil rights and legal procedures, and, in fact, law enforcement officials of both countries subsequently said that avoiding overreaction to the terrorist threat was a key factor in eliminating it.

Americans now would be well advised to heed that advice, several experts said. Law enforcement authorities should step up surveillance and intelligence gathering, but should avoid heavy-handed tactics that could play into the extremists’ hands, they argued.

Robert A. Wood, a political science professor at North Dakota State University, has studied far-right groups, including the Michigan Militia, which has been tentatively linked to individuals involved in last Wednesday’s bombing.

Wood urged both greater police activity and a response that avoids unintended consequences. Police agencies, Wood said, should immediately step up monitoring of the militias “because I think there is the potential that some of these groups may engage in illegal activities.”

The pitfall to avoid, Wood said, is alienating law-abiding residents by taking measures that drastically erode people’s sense of freedom.

“You want to maintain security on the one hand,” Wood said, “you don’t want to alienate the population with things that (resemble) martial law. . . . What a lot of terrorists would like to see with events like (the Oklahoma City bombing) is to spread fear and alarm. And if you overreact, you help terrorists do their job for them.”

Yet some new procedures may be required. One federal law enforcement agent, involved in a deadly standoff 2 1/2 years ago with a survivalist in Idaho, said he does not believe that authorities have adequate tools to protect the country from well-organized, trained terrorists. The agent, who did not want to be identified, said that court decisions and administrative policies have made it too difficult to effectively penetrate groups that might be bent on terror.

John C. Gibbons, a former federal prosecutor who heads a counterespionage consulting firm in San Francisco, said that the current restrictions were an appropriate response to illegal overreaching by federal and local authorities during the 1960s and 1970s.

“But those (restrictions) don’t deal with some of the realities we have to deal with today,” Gibbons said. “The Justice Department is going to have to develop new guidelines” that both safeguard civil rights and enable federal agents to more effectively prevent Oklahoma City-type acts.

Thomas R. Parker, a retired FBI agent who helped lead the bureau’s successful penetration two years ago of an Orange County-based group of skinheads that plotted to gun down parishioners of a black church in Los Angeles, said authorities already have adequate flexibility.

To lawfully penetrate a group, Parker said, agents “have to have a reason to think (group members) are going to be a part of some criminal activity. . . . There has to be legitimate probable cause.”

Parker, now a private security consultant, said he fears a stampede of overreaction. “When a Democratic government reacts by becoming more restrictive of political dissent, it can be just as damaging as was the terrorist act itself,” Parker said.

Bruce Hoffman, a former RAND Corp. specialist in terrorism, now at St. Andrews University in Scotland, sympathized with the plight of the agents.

“It’s hard now for authorities to act,” Hoffman said. “. . . They can only do monitoring after an incident. It’s now time to do something to make laws less restrictive so the FBI can monitor these groups.”

In light of Oklahoma City, Hoffman said: “The public as well as law enforcement officials should pay more attention to them and not just write them off as kooks and clans playing soldiers.”

Times staff writer Robin Wright and researcher D’Jamila Salem contributed to this story.