Between 1921 and 1923, several members of the Osage Indian Reservation died under suspicious circumstances. The FBI became involved after the Department of Interior wrote to Director William J. Burns requesting assistance in investigating these deaths. William "King of Osage" Hale was suspected of being involved in the deaths. Posing as medicine men, cattlemen, and salesmen, FBI agents infiltrated the reservation and solved the murders. Hale and other members of the Osage Indian Tribe were convicted and sentenced to life in prison, It was determined that the murders were committed in an attempt to collect insurance money and gain control of valuable oil properties owned by the deceased persons.