newlyweds john and pam branum are trying to start a family with no success. so, as a last resort they go to a fertility clinic here on the campus of the university of utah. a friendly lab technician shows them a photo collage above his desk, of babies conceived by artificial insemination. >> and, you know, i just looked at those pictures and i thought, "this is gonna be it!" maybe this is gonna happen for us. >> reporter: but something about the lab tech doesn't sit right with john.

pam branum swabbed the whole family. >> i thought it was really interesting how it tells you about yourwhere you come from. >> reporter: as expected, when the results come back, pam finds that annie shares 50% of her mom's dna. but what about her dad? >> and it said that they shared zero dna. i was in a panic. you know, i was in a complete panic. >> annie walked through the door, didn't say a word, gave me a big hug, started sobbing. >> i think it took a very long time for it to sink in. >> reporter: what was it that sunk in? >> trying to comprehend what it meant that he wasn't my biological father. and then, who is? >> reporter: the branums says for months they couldn't get answers from the university. it would take a dna detective to get to the bottom of it. >> they wanted to know what her biological heritage was on her paternal side. and i'm well known for doing that. >> reporter: finding biological fathers is a specialty of cece moore, a genetic genealogist in southern california. desperate for answers pam sends her an e-mail. >> this is right up my alley. >> reporter: she tells pam