The envelope was post marked Jan. 8, 1990, and addressed to "First Presidency You Devils."
The handwritten letter inside discussed someone by name: Gordon B. Hinckley.
"You will never become president because I will kill you first," the letter read. Those last three words were written in large letters in the center of the page.
The death threat is recounted as part of a 432-page FBI file discussing the late LDS President Hinckley. The Salt Lake Tribune requested the file under the Freedom of Information Act after Hinckley's death almost two years ago. The FBI released it this month.
The documents also detail how in 1997 a Seattle man sent threatening letters to Hinckley and the University The death threats sent to the late LDS President Gordon B. Hinckley. of Utah. The man wanted the university to forgive his $24,000 in student loans and demanded help from Hinckley.
LDS Church spokesman Scott Trotter on Thursday acknowledged "occasional threats" against church leaders over the years.
"When they occur they are referred to law enforcement officials for proper follow-up," Trotter said in a statement. He declined further comment.