FBI agents extracted false information by subjecting potential witnesses in the Navajo tribal officer murder investigation to grueling and leading interrogations, charges a motion filed Thursday in U.S. District Court.

The motion was filed by Loren E. Weiss, lawyer for Ben Atene Jr., one of the four men charged with the murders. Also charged are Thomas Cly, Vinton Bedonie and Marques Atene.They are charged with murdering officers Andy Begay and Roy Lee Stanley in a remote part of Monument Valley, San Juan County, in the early morning of Dec. 5, 1987.

The motion says the indictment should be dismissed and witness statements should be suppressed because of "the outrageous conduct of agents of the government." A hearing in the case is set for July 11.

The motion says FBI agents interviewed potential witnesses in Kayenta, Ariz. The same person may have been interviewed four or more times, and polygraph tests were administered. After each test, the motion says, each person was told he failed the lie detector test and that he would go to jail or be prohibited from seeing his family, unless he told the agents what they wanted to hear, the motion says.

"Each person was afraid of the agents. Each person was read a statement or questioned by the agents in a very leading fashion," it continues. "Only when they concurred with what the agents demanded, were these people allowed to leave."