More than 100 days into the search for Nancy Guthrie, could a breakthrough be sitting in an FBI lab as we speak? WHAT is taking so long?

The disappearance of Today show host Savannah Guthrie’s mother from her Tucson, Arizona home has gripped us since day one. Authorities say DNA evidence is now being analyzed at the FBI lab in Quantico, a move that suggests investigators believe it could be critical to finally bringing answers in Nancy’s disappearance.

Forensic DNA expert Tiffany Roy has processed thousands of DNA samples and worked on thousands of cases – it’s her job to review cases that have been processed by private and government labs, and make sure all procedures have been followed correctly.

So… have they?

We ask her what she believes is happening behind the scenes in Nancy’s case, and whether she thinks the Pima County Sheriff’s Department made a mistake in their process.

With no arrest and no suspect publicly named, what will it take to find answers and bring Nancy home?