EUGENE, Ore. (AP) -- A federal agent in an unmarked vehicle monitored a Eugene demonstration against the use of pesticides in highway ditches and called local police when one protester dressed as an exterminator started blocking traffic.
Federal officials told the Eugene Register-Guard newspaper that the officer was protecting the federal courthouse five blocks away.
Eugene police, who hadn't been at the May 30 rally, sent officers.
One used a stun gun on the protester and arrested two more people, leading to excessive force complaints against the police. Prosecutors are considering charges against the protesters.
The event was organized by a University of Oregon student group, Crazy People for Wild Places.
David Fidanque, executive director of the Oregon branch of the American Civil Liberties Union, said he would alert the national office that federal agents are monitoring legal demonstrations away from federal property.
He called it a chilling effect on free speech and free assembly.
Copyright 2008 The Associated Press.