Jimmy Duncan

Jimmy Dean Duncan was identified as the lead suspect in the 1975 home invasion rape and murder of 19-year-old Deborah Tomlinson in Grand Junction, Colorado. The case was cleared by exception due to the death of Duncan.

On December 27, 1975, an intruder had broken into Tomlinson’s home. She was bound, sexually assaulted, and strangled to death. Her body was found in her bathtub when the building manager telephoned police for a welfare check.

The FGG investigation was conducted by Parabon Nanolabs. Duncan, who was 26 years-old at the time of the murder, is reported to have passed away in 1987. The DNA match was confirmed with the assistance of an unspecified living relative, who cooperated with investigators.


CBS 4 News. “Grand Junction Cold Case Murder of Deborah Tomlinson Solved After 45 Years.” CBS 4 News Denver, December 2, 2020. Accessed December 13, 2020. https://denver.cbslocal.com/2020/12/02/grand-junction-cold-case-murder-deborah-tomlinson-jimmy-dean-duncan/?fbclid=IwAR33BfjuVqIf8FeNbrVqzr_s08Nnq8YOKQWQWB1nMMcHoG3c8qqYXW_gjHs.

Corey, Calvin. “Cold Case: GJPD Solves 45-Year-Old Homicide Case Involving Deborah Tomlinson.” NBC 11 News, December 2, 2020. Accessed December 13, 2020. https://www.nbc11news.com/2020/12/02/cold-case-gjpd-solves-45-year-old-homicide-case-of-deborah-tomlinson/.

Reader, Grace. “GJPD Corporal Reopens Deborah Tomlinson Case, Demands Justice for Family.” KJCT 8 News, March 26, 2019. Accessed December 13, 2020. https://www.kjct8.com/content/news/GJPD-corporal-reopens-Deborah-Tomlinson-case-demands-justice-for-family-507704961.html.


First Name Jimmy
Last Name Duncan
Other Names
Victims 1 (Details)
IGG Started 2020-00-00
Case Cleared 2020-12-02
IGG Org Parabon


Case ID Name Age Case Opened Location Investigating Org Most Serious Charge Disposition Court
1439 Deborah Tomlinson 19 1975-12-27 Grand Junction, CO Grand Junction PD Second degree murder Case was cleared by exception due to death of perpetrator n/a

Last updated: February 9, 2024

To contribute information on new or existing IGG cases, use this form.

Case data and narrative licensed under CC BY 4.0: Dowdeswell, Tracey (2023), “Forensic Genetic Genealogy Project v. 2022”, Mendeley Data, V1, doi: 10.17632/jcycgvhm96.1. All other content, including photos, have been added.