Episode 172: Weysan Dun – Posse Comitatus, Nebraska Cult Murders

Retired agent Weysan Dun served in the FBI for 30 years. During his time in the field, he worked counter-intelligence, high-technology theft, domestic terrorism, and violent crime matters. In this episode of FBI Retired Case File Review, Weysan reviews a case targeting an extremist group espousing Posse Comitatus rhetoric and white supremacist views. Initially under investigation for weapons and interstate theft violations, the cult leader, Michael Ryan, his fifteen-year-old son Dennis, and others were charged and convicted of the violent and horrific deaths of two group members.

After the successful conclusion of the case, Weysan Dun steadily moved up the ranks of the FBI, serving in a variety of mid-level leadership and management positions. He received numerous awards, including the Presidential Meritorious Executive Rank Award conferred by the President of the United States in recognition of sustained leadership and accomplishment. At the time of his retirement, he was the longest-serving, incumbent Special Agent in Charge (SAC), consecutively serving as the head of the Springfield, Illinois Division; the Newark, New Jersey Division; and the Omaha Division for a total of nine years.

Appointed by the Governor of Nebraska, Weysan Dun currently serves as a commissioner of the Nebraska Crime Commission. He also sits on several boards, including the Omaha Police Foundation. He is active as a community volunteer leader for the American Red Cross.

Special Agent in Charge (Retired)

Weysan Dun

April 1982  –  April 2012

“Based on what Rick and the other people who had confessed had told us, we had a pretty rough idea where the bodies were supposedly buried.”   —— Retired agent Weysan Dun

The following are links to articles about the investigation, arrest, and conviction of Nebraska Posse Comitatus leader Michael Ryan, his fifteen-year-old son Dennis, and others convicted of first degree murder:

Lincoln Journal Star – 5/11/1983:  Neo-Nazi literature found on raided Rulo farmstead;  Posse

Lincoln Journal Star – 8/23/1985: Extremists’ groups threats fueling concern of FBI


Chicago Times – 11/16/1987:  NIGHTMARE IN RULO

The Columbus Telegram – 12/30/1987:  Survivalist Groups lose support after Rulo incident

Daily Beast – 4/4/2017:  Nebraska Cult Killer Michael Ryan Cheats Death Row

The story of Mike Ryan and his son Dennis, seen here in a 1984 photo, is documented in the true crime book “Evil Harvest” written by Rod Colvin.











Jerri Williams

View posts by Jerri Williams
Jerri Williams, a retired FBI agent, author and podcaster, jokes that she writes about the FBI to relive her glory days. After 26 years with the Bureau specializing in major economic fraud and corruption investigations, she calls on her professional encounters with scams and schemers to write police procedurals inspired by true crime FBI cases in her Philadelphia FBI Corruption Squad crime fiction series featuring flawed female FBI agent Kari Wheeler. Jerri’s FBI for Armchair Detectives nonfiction series enables readers to discover who the FBI is and what the FBI does by debunking misconceptions about the FBI in books, TV, and movies. Her books are available as ebooks, paperbacks, and audiobooks wherever books are sold. She’s also the host of FBI Retired Case File Review, a true crime podcast with more than 300 episodes available on all popular podcast apps and YouTube.

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