The head of the Navajo Nation police department has high praise for Federal Bureau of Investigation agents who arrested four men in connection with the brutal slayings of two tribal police officers.

The investigation of the slayings of Navajo Police Officers Roy Lee Stanley and Andy Begay, found dead Dec. 5 in a smoldering police van on the Navajo Indian Reservation, has been frustrating and fraught with cultural complexities, FBI agents said.More than 100 residents of Monument Valley in San Juan County, where the slayings occurred, were interviewed during the 4-month investigation. Agents met with recalcitrant Navajos, some fearing witchcraft, unwilling to implicate others.

"They (the FBI) were sensitive to the culture here," said Col. Bill Kellogg, director of public safety for the tribe. His office was subordinated by the bureau's jurisdiction over killings on Indian reservations.

"In fact, they went out of their way not to offend anyone," he said.

Kellogg pointed to personal appearances in Monument Valley by Assistant U.S. Attorney David Schwendiman and Robert Bryant, head of Salt Lake City's FBI office, as illustrative of a respectful investigation.

"I thought that was very good; it showed they did care, and I think the people respect them for doing that," he said, adding that he saw no animosity among Navajos toward outside investigators.

FBI agents have, however, observed that cultural barriers and an aversion to FBI intervention have burdened the investigation, causing witnesses to balk at providing officials with sufficient evidence for four months.

"That's not very long," Kellogg said. "I know of cases (on Indian reservations) that have been years until they've come up with answers."

Agents assembled enough probable cause by last Friday to arrest and charge four Navajos Thomas Cly and Marques Atene, both 22, Vinton Bedoni, 31, and Ben Atene Jr. 24 in connection with the slayings. All four were apprehended in Monument Valley.

The arrest of the four doubled the tragedy of the loss of officers Stanley and Begay, Kellogg said.

"That takes a big resource from a small community like that; that's the tragedy of the whole thing," he said.

Some Navajo tribal officials have expressed a desire to wrest jurisdiction over major crimes such as murder committed on Indian reservations from federal authorities, who currently have jurisdiction under the Major Crimes Act.

But tribal law enforcement "is a long way from that," Kellogg said, adding that reservation authorities have neither the finances nor the facilities, including adequate jails and crime laboratories, to handle such cases.

One law-enforcement official familiar with the investigation said the family of one slain officer asked for police protection from those seeking revenge for the recent arrests. Another family boasted there would be vigilante justice for others involved in the crime who were not arrested, said the official, who requested anonymity.

But Kellogg disputed those claims, saying, "I spent the last three days in the valley and everything is very peaceful."