``During the course of this investigation, no indications of crime developed,'' Thomas Carey, assistant special agent in charge of the investigation into the death of the Rev. John Kaiser, said at a news conference.
Kaiser, 67, was found dead along a busy highway Aug. 24, with a gunshot wound to the right side of his head. His shotgun was found near him, and his pickup truck was 33 feet away in a ditch.
``The manner of Father Kaiser's death is most consistent with death resulting from a self-inflicted gunshot wound to the head,'' Carey said.
The idea that Kaiser committed suicide has been rejected by colleagues who believe he was killed for criticizing the Kenyan government.
A Roman Catholic priest from Perham, Minn., and a member of the Mill Hill order, Kaiser had been working in Kenya for 35 years, mostly in remote rural areas in the southwest part of the East African country.
He had been actively involved in publicizing alleged official human rights abuses during politically instigated tribal clashes and alleged sexual abuse of some of his young female parishioners by Julius Sunkuli, a minister in the office of President Daniel arap Moi.
Sen. Paul Wellstone, a Minnesota Democrat who has pushed for a thorough probe into Kaiser's death, said he was ``very, very skeptical'' of the FBI report and claimed the investigation was carried out ``in a climate of fear.''
He promised Kaiser's family and friends that he would continue his campaign in Washington.
``We express our shock and our outrage - our quiet outrage - but we are determined to carry on,'' Wellstone said in St. Paul, Minn.
The unsolved deaths of several prominent Kenyans in the past two decades have been called as suicides.
Carey and four other FBI agents said all leads had been followed, more than 200 interviews conducted and a leading gunshot-wound analysis expert consulted in the course of the investigation, which was requested by Kenyan Attorney General Amos Wako the day after Kaiser's body was found.
Wako acknowledged that the Kenyan police's unimpressive record in investigating other politically sensitive deaths would have made a unilateral Kenyan investigation suspect. He said he had immediately requested FBI help in investigating Kaiser's death.
Under Kenyan law, reports of suspected homicides prepared by the Criminal Investigations Department are not made public unless prosecution is undertaken or a public inquest is ordered.
The 82-page ``final report'' into Kaiser's death refers several times to medical reports that indicated Kaiser suffered from manic-depression and that he had been hospitalized several times for ``mental problems.''
It includes a timeline detailing what appears to be Kaiser's increasingly erratic behavior in the 96 hours before his death.
Carey said Dr. Vicent Di Maio, chief medical examiner in Bexar County, Texas, concluded the wound that caused Kaiser's death was self-inflicted. Di Maio did not see the body, but he had access to morgue photos.
The U.S. Embassy in Nairobi issue a press release that referred to the ``considerable speculation in Kenya and the United States that Father Kaiser's death was directly linked to his political activities.''
``The FBI investigated these political allegations - that he had been killed because he had angered people in power - especially thoroughly and in the end found nothing to support a charge of murder against any of the individuals implicated,'' it said.