The tech helping crack decades-old cold cases

Randy Gail Sperino was last seen alive on the evening of 9 November 1993, as she was getting into a pickup truck in Granite City, Illinois.

The 34-year-old's body was found hours later in a field nearby, the victim of blunt force trauma.

The identity of her killer was a mystery. DNA evidence found at the crime scene was tested against standard law enforcement databases, but no matches were found.

For three decades, investigators from the Madison County Sheriff's Office…