A decades-old Colorado cold case might just one step closer to being solved.
How Many Cold Cases Remain Unsolved in the U.S.?
Between the years of 1965 to 2023, approximately 345,000 cases of homicide and “non-negligent manslaughter” went unsolved, according to the official Project Cold Case website.
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Who Was Rosa Arguello?
In 2003, a 29-year-old from Colorado named Rosa Arguello was found dead from multiple stab wounds in Thornton, according to CBS reports.
The Night of the Murder in Thornton
Her remains were found on the side of the road in the 12000 block of Quebec Street on October 17th of that year.
Arguello was living in Thornton with her children at the time. She also was a member of the Hopi Tribe.
Break in the Thornton Murder Case: Suspect Arrested After 22 Years In Iowa
For nearly 22 years, her case ran cold. However, a possible suspect in this murder case was arrested hundreds of miles away in the Midwest.
On Monday, September 15th 2025, law enforcement from Dubuque, Iowa arrested 55-year-old Robert McClain. This was on a homicide warrant out of Adams County. Officials searched his home and found him in possession of a firearm as a felon, according to reports.
Who Is Robert McClain?
This man has a criminal history of disturbing acts of violence, reports say…