In 2005, a quiet town in Idaho was shattered by a crime so brutal it shocked the entire country. A man with a long, violent past slipped through the cracks of the justice system and into the lives of one family—with devastating consequences. What followed was a nightmare that crossed state lines, exposed failures in the system meant to stop predators, and left behind a story of unimaginable horror… and one survivor whose testimony would reveal just how far evil can go.

This episode unpacks the chilling trail of Joseph Duncan III—the warnings that were missed, the crimes that escalated, and the case that still haunts investigators to this day.

Sources

[1] Joseph Edward Duncan - Wikipedia https://en.wikipedia.org/wiki/Joseph_Edward_Duncan

[2] In 2005 Joseph Duncan killed three members of the Groene family ... https://www.reddit.com/r/serialkillers/comments/hannh7/in_2005_joseph_duncan_killed_three_members_of_the/

[3] Man in Idaho case has sex crime history - NBC News https://www.nbcnews.com/id/wbna8446152

[4] Joseph Edward Duncan III - Crime Library https://crimelibrary.org/serial_killers/notorious/joseph_duncan/

[5] Idaho suspect's records show violent history - NBC News https://www.nbcnews.com/id/wbna8485031

[6] Joseph Duncan III | Criminal Minds Wiki - Fandom https://criminalminds.fandom.com/wiki/Joseph_Duncan_III

[7] Convicted serial killer who murdered 10-year-old Beaumont boy 24 ... https://rivcoda.org/news/convicted-serial-killer-who-murdered-10-year-old-beaumont-boy-24-years-ago-dies-indiana

[8] Joseph Duncan III was an American pedophile and serial killer most ... https://www.reddit.com/r/CreepyWikipedia/comments/1bgs61q/joseph_duncan_iii_was_an_american_pedophile_and/

[9] The Groene Case - CBS News https://www.cbsnews.com/pictures/the-groene-case/

[10] United States v. Duncan, III, No. 08-99031 (9th Cir. 2011) - Justia Law https://law.justia.com/cases/federal/appellate-courts/ca9/08-99031/08-99031-2011-07-11.html

[11] Joseph Duncan III | Photos 2 https://murderpedia.org/male.D/d/duncan-joseph-edward-photos-2.htm

[12] I Survived the Serial Killer Who Murdered My Family https://www.oprahdaily.com/life/wholeness/a65383797/shasta-groene-survival-story/

[13] [PDF] Former jurors still haunted by Idaho trial of Joseph Duncan III https://www.courts.wa.gov/content/PublicUpload/eclips/Clips%20The%20Olympian%2002.11.13.pdf

[14] Convicted Child Murderer Joseph Edward Duncan, III, Dies on ... https://www.justice.gov/usao-id/pr/convicted-child-murderer-joseph-edward-duncan-iii-dies-death-row

[15] Serial Killer Documentary: Joseph Edward Duncan (The Boogeyman) https://www.youtube.com/watch?v=UbXcZkrNp7k