Joseph Greene , a U.S. immigration agent , testified in court that FBI agents had learned of the assassination plot from a member of the organization who was in a witness protection program . Greene said that members involved in the assassination plot included Ma Anand Sheela , Dianne Yvonne Onang , and Alma Peralta . The assassination plot was investigated by the FBI and the Oregon State Police . Informants told law enforcement that Ma Anand Sheela hoped Turner 's death would prevent an Immigration and Naturalization Service investigation which she thought could lead to Rajneesh 's arrest and deportation from the United States . Weaver stated " These attempts to assassinate public officials were because they were presenting an immigration case that might result in imprisonment " of Rajneesh . " It were not simply plans , but at least one ( assassination ) attempt , " said Weaver at the hearing .