Investigators zero in on DNA found in Nancy Guthrie home and question gun shop owners

IN THE AREA WITH A LIST OF NAMES AND PHOTOS OF MEN. OF. PHOTOS OF MEN. ARE THESE PERSONS OF INTEREST? INTEREST? NBC'S LIZ KREUTZ IS IN TUCSON WITH THE NEW. NBC'S LIZ KREUTZ IS IN TUCSONON WITH THE NEW INFORMATION. TUCSON WITH THE NEW INFORMATION. >> Reporter: TONIGHT. INFORMATION. >> Reporter: TONIGHT ASAS INVESTIGATORS ZERO. >> Reporter: T TONIGHT AS INVESTIGATORS ZERO IN ON THE UNKNOWN DNA. IN ON THE UNKNOWN DNA FOUND AT NANCY GUTHRIE'S HOME, NBC. FOUND AT NANCY GUTHRIE'S HOMEME, NBC NEWS IS LEARNING MORE. NEWS IS LEARNING MORE ABOUT HOW THEY ARERE ALSO CANVASSING GUN. ABOUT HOW THEY ARE ALSO CANVASSING G GUN STORES ACROSS TUCSON. ALSO CANVASSING GUN STORES ACROSS TUCSON TRYING TO IDENTIFY THE. STORES ACROSS S TUCSON TRYING TO IDENTIFY THE ARMED SUSPECT. ARMED SUSPECT. OWNERS OF TWO DIFFERENT GUN SHOPS. OWNERS OF TWO DIFFERENT GUN SHOPS TELL US INVESTIGATORS. DIFFERENT GUN SHOPS TELL US ININVESTIGATORS CAME TO THEIR STORE. CAME TO THEIR STORE WITH A LIST OF NAMES THREE TO FOUR PAGEGES. WITH A LIST OF NAMES THREE TO FOUR PAGES LONG, INCLUDING PHOTOS. THREE TO FOUR PAGES LONG, INCLUDING PHOTOS OF PEOPLE PATIO. LONG, INCLUDING PHOTOS OF PEOEOPLE PATIO TENSION PEOPLE OF.

TENSION PEOPLE OF INTEREST. ONE DIDN'T RECOGOGNIZE. INTEREST. ONE DIDN'T'T RECOGNIZE OR SELL A GUN TO. ONE DIDN'T RECOGNIZEZE OR SELL A GUN TO ANYONE ON THE LIST. OR SELL A GUN TO ANYONE ON THE LIST.. THE OTHER SAYS ALL THE. ANYONE ON THE LIST. THE OTHEHER SAYS ALL THE PHOTOS WERE OF YOUNG. THE OTHER SAYS ALL THE PHOTOS WERE OF YOUNG TO MIDDLE-AGED MEN. PHOTOS WERE OF YOUNG TO MIDIDDLE-AGED MEN. MEANWHILE THE SHERIFF. MEANWHILE THE SHERIFF SAYS THE UNKNOWN D DNA FOUND AT THE HOME IS A. SAYS THE UNKNOWN DNA FOUND AT THE HOME IS A MIXTURE WHICICH CAN TAKE. FOUND AT THE HOME IS A MIXTURURE WHICH CAN TAKE A LONG TIME TO. A LONG TIME TO PROCESS. THE FACT THAT IT MAY. PROCESS. THE FACT THAT IT MAY BE A MIXTURERE IS MORE. THE FACT THAT IT MAY BE A MIXTURE IS MORE COMPELLING BECAUSE. BE A MIXTURE IS MORE COMPELLING BECAUSE THAT IS SO COMMON IN. COMPELLING BECAUSE THAT IS SO COMMON IN VIOLOLENT CRIMES. VIOLENT CRIMES. WE KNOW THERE WAS SOME TYPE OF ALTERCATION. WE KNOW THERE WAS SOME TYPE OF ALTERCATION THAT CAUSED NANCY Y TO. TYPE OF ALTERCATION THAT CAUSED NANCY TO BLEED. THAT CAUSED NANCY Y TO BLEED. AND SO, HOPEFULLY, T. AND SO, HOPEFULLY, THAT MEAEANT SHE FOUGHT BACK AND WAS ABLE TO.

THAT MEANT SHE FOUGHT BACK AND WAS ABLE TO CREATE A DNA SAMPLE. BACK AND WAS ABLE TO CREATE A D DNA SAMPLE THAT CAN BE USED FOR. CREATE A DNA SAMPLE THAT CAN BE USED FOR ANALYSIS. THAT CAN BE USED FOROR ANALYSIS. >> Reporter: THE. E. >> Reporter: THE SHERIFF SAYS THEY ARE TURNING TO. TURNING TO INVESTIGATIVE GENETIC GENEALOGY USING PUBLIC. INVESTIGATIVE GENETIC GENEALOGY USING PUBLIC DNA DATABASES TO TRY. DNA DATABASES TO TRY TO IDENTIFY WHOSE DNA IT IS. IT IS. WAS THE DNA SAMPLE TAKEN FROM A PLACE. WAS THE DNA SAMPLE TAKEN FROMOM A PLACE THAT IT'S POSSIBLE THE. THAT IT'S POSSIBLE THE SUSPECT COULD HAHAVE BEEN? SUSPECT COULD HAVE BEEN? >> I AM NOT GOING TO. BEBEEN? >> I AM NOT GOING TO GET INTO ITS ACTUAL. GET INTO ITS ACTUAL LOCATION.. BUT, YES, WE BELIEVE. LOCATION.. BUT, YES, WE BELIEVE THAT WE MAY HAVE SOME. BUT, YES, WE BELIEVE THAT W WE MAY HAVE SOME DNA THERE THAT MAY BE. THAT WE MAY HAVE SOME DNA A THERE THAT MAY BE OUR SUSPECT. OUR SUSPECT. >> Reporter: RECENT YEARS, GENETIC. >> Reporter: RECENT YEARS, GENETIC GENEALOGY HAS. YEARS, GENETIC GENEALOGY HAS SUCCESSFULLY.

GENEALOGY HAS SUCCESSFULLY IDENTIFIED OTHER. SUCCESSFULLY IDENTIFIED OTHER HIGH-PROFILE C CRIMINALS. IDENTIFIED OTHER HIGH-PROFILE CRIMINALS LIKE THE GOLDEN STATE. HIGH-PROFILE CRIMINALSLS LIKE THE GOLDEN STATE KILLER AND RYAN. KILLER AND RYAN KOHBERGER. IN T THAT CASE, IT TOOK. KOHBERGER. IN THAT CASE, IT TOOK SEVERAL WEEKS TO FIND. IN THAT CASE, IT TOOK SEVERAL WEEKS TO FIND A MAMATCH. SEVERAL WEEKS S TO FIND A MATCH. >> HER KIDNAPPER. >> HER KIDNAPPER SHOULD BE VERY SAY FRFRAYED BECAUSE HE. FRAYED BECAUSE HE DEFINITELY GOING TO BE IDENTIFIED THROUGH. DEFINITELY GOING TO BE IDENTIFIFIED THROUGH THIS METHOD IF NOTHING. THIS METHOD IF NOTHING ELSE WORKS. IT'S REALLY JUSTST A. ELSE WORKS. IT'S REALLY JUST A MATTER OF TIME. IT'S REALLY JUST A MATTERER OF TIME. IT'S GOING TO BE. MATTER OF TIME. IT'S GOING TO BE HOURS,S, DAYS OR WEEKS, HOURS, DAYS OR WEEKS, BUT HE IS GOING TO BE CAUGHT. BUT HE IS GOING TO BE CAUGHT. >> LIZ JOINS US LIVE. CAUGHT. >> LIZ JOINS US LIVE. WE KNOW TUCSON IS VERY. >> LIZ JOINS US LIVE. WE KNOW TUCSON IS VERY CLOSE TO THE MEXICO. CLOSE TO THE MEXICO BORDER. DO WE KNOW IF. BORDER. DO WE KNOW IF OFOFFICIALS HAVE SPOKEN. DO WE KNOW IF OFFICIALS HAVE SPOKEN WITHTH THE MEXICAN.

OFFICIALS HAVE SPOKEN WITH THE MEXICAN AUTHORITIES? WITH THE MEXICAN AUTHTHORITIES? >> Reporter: YEAH, AUTHORITIES? >> Reporter: YEAH, TOM, YES. >> Reporter: YEAH, TOM, YES. TWO OFFICIALS BRIEFED. TOTOM, YES. TWO OFFICIALS BRIEFED ON THE CASE SAY LAW. TWO OFFICIALALS BRIEFED ON THE CASE SAY LAW ENFORCEMENT HAS BEEN. ON THE CASE SAY LAW ENFORCEMENT HAS BEEN IN TOUCH WITH.