DNA science has helped solve criminal cases for decades. But increasingly, investigative genetic genealogy — which was first used for cold cases — is helping to solve active cases as well.

Federal and local authorities will use genetic genealogy to analyze DNA found at Nancy Guthrie's home as the ongoing investigation into her possible abduction stretches into its third week.

Joseph Scott Morgan, forensic expert, details the crucial role of DNA evidence in the search for missing Nancy Guthrie. He explains advanced genetic testing, including the use of genealogical ...