Article continues below advertisementAs Nancy Guthrie remains missing, the public continues to question what could've happened to the Arizona retiree. Retired SWAT commander Bob Krygier believes it's only a matter of time, though, before "good old-fashioned police work" leads to a break in the befuddling case.In an interview published on March 9, Krygier said that "following up on leads, knocking on doors [and] working hand in hand with all investigators and with the public" is what will ultimately produce answers.