DUBUQUE, Iowa – On Monday, September 15, 2025, at approximately 10:51 a.m., the Dubuque Police Department arrested 55-year-old Robert McClain, a Dubuque resident, on a warrant issued by Adams County, Colorado, charging him with homicide in connection to a long-standing cold case.

The arrest follows a collaborative investigation sparked by information received by Dubuque Police, indicating McClain’s potential involvement in the Colorado homicide. The Dubuque Police Department promptly shared this lead with the Thornton Police Department in Colorado, who led the subsequent investigation with support from Dubuque authorities.

“This arrest demonstrates the power of inter-agency cooperation in bringing closure to cases that have remained unsolved for years,” said Lt. Luke Bock of the Dubuque Police Department. “We are committed to assisting our partners in Thornton as they move forward with this case.”

Details surrounding the homicide remain limited, and all inquiries regarding the investigation are being directed to the Thornton Police Department Public Information Office, reachable at tpd.pio@thorntonco.gov or 720-441-4630.

As with all criminal cases, the charges against McClain are allegations, and he is presumed innocent until proven guilty in a court of law.