Attorneys for four Navajo men accused of killing two tribal policemen are seeking a dismissal of murder charges against their clients for reasons related to the FBI's investigation of the slayings, lawyers say.

Vinton Bedoni, 31, Ben Atene Jr., 24, Marques Atene, 22, and Thomas Cly, 22, are scheduled to stand trial in federal court next week on charges of first-degree murder on an Indian reservation and aiding and abetting in the deaths of officers Andy Begay and Roy Lee Stanley.The officers' bodies were found in their burned-out police van in Monument Valley Dec. 5. Investigators said the two appeared to have been killed after they tried to break up a drinking party at a site west of Gouldings, San Juan County, the night before.

A pre-trial hearing for the four defendants was held Tuesday before U.S. District Judge J. Thomas Greene, at which time defense attorneys indicated they would seek a dismissal of charges on grounds of government misconduct.

Loren Weiss, representing Ben Atene, said afterward that a dismissal motion and another seeking the suppression of certain statements taken during the investigation was to be be filed Wednesday in U.S. District Court.

Weiss would not elaborate on the content of the motions but said allegations of FBI coercion of witnesses was "certainly part of it."

The arrests of the four defendants in April capped a difficult investigation in which authorities interviewed more than 100 tribal members.

The FBI said suspects had been identified as early as February but witnesses were reluctant to testify because they apparently feared retribution.

Greene is expected to hear arguments on the motions the morning of July 11 morning, with jury selection to follow later that day or July 12.