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Finding a Serial Killer – and Justice – After 40 Years

NCJ Number
Date Published
January 2023

This podcast episode features a conversation between host Kara Friedman, detective Kari Johnson, and Dr. Angela Williamson, about how decades of police work and cutting-edge forensic science helped identify Joe Michael Ervin as the serial killer responsible for four murdered women between 1978 and 1981.


In this Justice Today episode, host and director of Criminal Justice Innovation, Development, and Engagement at the Office of Justice Programs’ Bureau of Justice Assistance (BJA) speaks with detective Kari Johnson, of Denver, Colorado, and Dr. Angela Williamson, the forensics unit supervisor at BJA. The three podcasters discuss the Denver police announcement that they had solved the cold-case murders of four women who were killed about 40 years ago. They discuss the efforts of the law enforcement officers in charge of the investigation, using old-school police work combined with cutting-edge investigative technique called forensic genetic genealogy; the investigation also required collaboration of police in Colorado and Texas, as well as support from BJA. This episode’s guests were instrumental in solving the cold-case murders, and in the episode they walk listeners through the story of the detective-work that went into effect to identify Joe Michael Ervin as the serial killer responsible for the four murders.

Date Published: January 1, 2023