Dallas has thousands of unsolved murder cases, but with modern DNA technology, detectives at the Dallas Police Department are solving decades-long cold cases.

Finding a suspect What we know: Detective Andrea Isom and the Dallas Police Department's Cold Case Unit are working to track down suspects using DNA technology that did not exist when the crimes occurred.

This includes a DNA database containing DNA taken from people who have been arrested, as well as investigative genetic genealogy, using DNA left at a crime scene decades ago to map biological relationships and find a suspect.