zella mae jackson. a clue big enough for the twins to begin some online detective work. >> we looked her up on google. and it kept popping up zella jackson price and like, ? and i was like, maybe she's a singer. >> reporter: a singer with a following on youtube. her facebook page revealing a familiar gleam in her eye. did you see any resemblance? >> yeah. yeah. my twin sister looks like my grandma and then i see my grandma, her eyes, i say that's my mom's eyes. >> reporter: a striking resemblance. who could mistake it? so they decide to send zella this message. >> hello, my name is mehiska jackson. i believe that you're my grandmother and you're my mom's mom. >> what you say, baby? and she said, my mother was born november the 25th, 1965, in st. louis, missouri. at homer phillips hospital, does that ring a bell? >> reporter: it sure did. zella agrees to a dna test and guess what? it's a match. >> and it came out 90.997%, that's my baby. then secretly choreograph a virtual meeting with zella determined to

. >> she found a zella mae jackson and called her. didn't have a baby," so, i mean, what do you do at that point? >> reporter: though zella denies getting that call, u.s. attorney richard callahan is intrigued by those old records that are surfacing. >> that began to paint a different picture from what zella price was saying. >> reporter: so you began to see some discrepancies? >> well, the records were certainly contradicting the story. >> reporter: then he uncovers an explosive contradiction. one that will shake the stolen baby story to its core. callahan releases diane's birth certificate, and take a look. it says she was born at city hospital, not homer g. phillips as zella jackson-price claims. >> you sort of think, well, there can't have been a baby stealing ring running out of homer g. phillips, if the baby wasn't born at homer g. phillips. >> reporter: the bombs keep going off. you came here, your water had broke? >> yeah. >> reporter: coming up, time for tough questions. we bring zella back to the scene she's defensive and def