In a statement marking six months since Guthrie disappeared, Sheriff Chris Nanos said the joint task force of the Pima County Sheriff's Department and the FBI remains committed to finding her and providing answers to her family. The sheriff also said authorities will publicly announce any significant developments in the case when they occur.
"The analysis of DNA and digital evidence has been underway for the past six months," the department said. "This work is complex and time-intensive, but investigators continue to pursue every credible lead."
"It has been months since our mom was taken from us. Our family is in agony. We are in a nightmare that will not end," Savannah Guthrie said in a video posted to Instagram. She also appealed directly to anyone responsible or with knowledge of the case, saying, "I truly believe it is never too late to do the right thing."
Nancy Guthrie disappeared during the early morning hours of Feb. 1 from her home in Tucson's Catalina Foothills. Federal investigators are treating the case as a kidnapping.
The FBI previously released surveillance video showing an armed person dressed in dark clothing approaching the home before covering a Nest doorbell camera. Investigators have not publicly identified a suspect, announced any arrests related to the abduction itself, or said where Nancy Guthrie is.
The sheriff's department referenced Savannah Guthrie's recent appeal in Thursday's statement, saying, "it is never too late to do the right thing," before urging anyone with information to contact investigators and bring the case to a resolution.
The Guthrie family is offering a reward of more than $1 million for information leading to Nancy Guthrie, while the FBI continues accepting tips through 1-800-CALL-FBI. Anonymous tips also can be submitted through 88-CRIME in the Tucson area.
Recent discussion of the case included alleged ransom communications described by journalist Briana Whitney on the "Crime Junkie" podcast.