When a young schoolteacher in Pennsylvania is murdered, her friends wonder if the killer will be caught. Following years without an arrest, investigators discover a new tool that may finally help unlock the murderer’s identity. Can police work fast enough to catch the suspect? Or will the killer slip away again? Andrea Canning reports.

Listen to Andrea Canning and Josh Mankiewicz as they go behind the scenes of the making of this episode in ‘Talking Dateline’: https://link.chtbl.com/tdl_facingthemusic