U.S. District Judge J. Thomas Greene refused Tuesday to dismiss an indictment in the Navajo police slayings and refused to suppress statements by witnesses - even though some of them now say they lied.

Greene ruled against a defense contention that the FBI had coerced perjury from witnesses. He said there was no misconduct either by the FBI or the U.S. attorney's office.No evidence proving guilt was brought out during a daylong hearing Monday, and the grand jury most likely would have indicted the four defendants even with the latest changes in the case, Greene said.

He added that the problems cited Monday "relate to the credibility and reliability of witnesses, and the trial jury will take those matters into consideration." He noted that while some witnesses have changed their testimony, others have not.

Jury selection was to begin later Tuesday, and the actual trial is to start at 9 a.m. Friday.

The ruling was another twist in the strange case. Thomas Cly, Marques Atene, Vinton Bedonie and Ben Atene are charged with killing officers Roy Lee Stanley and Andy Begay, on Dec. 4, 1987.

One of the stranger aspects of Monday's testimony was that FBI special agent Timothy J. Healy said a magic ceremony was held on the Navajo reservation to thwart the investigation, witness Julius Crank told him.

"He said there was a ceremony to block the investigation, and that it was very strong, and it caused one of the medicine men to die."

Defense lawyers tried to have the indictment dismissed because of alleged government misconduct. In the hearing Monday, defense lawyer Walter F. Bugden Jr. denounced "a pattern of coercion and duress employed by the FBI."

Assistant U.S. Attorney David Schwendiman said, "We contest hotly there was a pattern of coercion."

Two defense witnesses corroborated the FBI's version, and the agents themselves testified they did not make unfair threats or promises and were not abusive. However, two admitted they raised their voices during questioning, and one said he had used an obscenity.

The agents said they wanted to get the truth from witnesses.

Participants sweltered during the 13-hour hearing after the courthouse's air conditioning was turned off.

"It's like one big sauna," Greene said of the heat.

In the hearing's highlights:

-Phillip Bosely Jr. testified that he was intimidated in questioning when handcuffs were laid on him by Officer Oliver James Seamans of the Bureau of Indian Affairs.

He was given a polygraph test and told he failed it. He wanted to call a lawyer, but a Navajo officer told him "if I did I would go to jail with him (the lawyer) also," Bosely said.

He claimed he gave a false statement under this pressure, making up details. He claims he wanted to recant, but FBI agent Healy "told us that if we changed this again we're going to jail, and this is where he took us." Healy drove Bosely and witness Boyd Grey to the Salt Lake City-County Jail and then away from the jail, he said.

So next day, when Bosely testified before the grand jury, he gave an untrue statement, he said. The truth is "I wasn't there" at the bonfire when the lawmen were killed, he said.

-Seamans denied the handcuff incident, and Healy, who was present for some of the questioning, said he never saw it either.

-Healy explained the trip to the jail by saying he showed Bosely and Grey the sights in Salt Lake City, including the LDS temple, the Federal Building, the marshal's office and the jail.

He said one witness who had changed her story told him she was afraid of retribution if she cooperated with the FBI, naming the brother of one of the defendants as a one she was afraid of.

Healy said it is true that when a witness failed a polygraph test he was told he had failed, and admitted he used an obscenity and shouted.

-Julius Crank, 21, said he gave false testimony when Healy and an FBI polygraph expert scared him. He said he was afraid that "they'd take me . . . to jail or something" if he didn't say what the FBI wanted.

So he made up testimony, based upon rumors, he said. "I did not go to the bonfire."

-Raymond Crank, 18, said the FBI "can't believe the truth," so he lied, as he was afraid of being arrested for perjury. He was told he failed a polygraph test, he said.

Most of his statement was handwritten by an agent, but he signed it. At the end was a disclaimer about the statement being true. He read that part out loud and didn't know what a word meant. He said he had taken it down at the FBI's dictation.

-Laura Tallis, 16, said agents "kept telling me the same thing, that I was there," when she wasn't. She said she was afraid she'd be handcuffed and taken from her family. "He (FBI agent James Downey) said it lots of times," she said.

"They told me about how the jail was," she said. "They told me about how they dress and how they eat."

She said she tried to tell the agents the truth, that she was home at the time of the killings.

"They didn't want to hear it," she said. "He (Downey) just kind of put the words in my mouth, and I said it, whatever he said."

On April 27, she told the grand jury that she was at the bonfire, that she had been forced to drive one of the officers' panel trucks to Copper Canyon. "They kept telling me that if I lied, right after the grand jury was over they were going to arrest me."

-Downey said he was careful not to supply details to witnesses. "We did not want them to feed back information," he said. "When I did not feel they were being truthful" he pointed out it was a violation of federal law to lie to an agent.