lynda whitehead: i was so nervous. i didn't know what to do. i was, like, "oh, my god. oh, my god." i was just shakin, i could hardly drive. keith morrison: lynda pulled into her daughter's neighborhood-- and saw a police officer. lynda whitehead: he said, "ma'am, can you pull over there." i said, "no, i need to go to my daughter's house." he said, "ma'am, will you just pull over there, please." and i pulled to the side. i said, "what is goin' on?" he said, "ma'am, the only thing i could tell you is your daughter has expired." keith morrison: there is no getting over news like that. as nikki's family tried to take it in -- investigators set to work figuring out who did this. the girls said their mother was still in her room with the door locked when they left the house for school at 7:30. jasmiyah whitehead: we missed the bus, so we had to walk. keith morrison: perhaps the crime scene would yield more clues than the girls could. lt. chris moon headed back there. detective chris moon: we're looking for-- cell phones, computers, indications, you know, typically-- victims are gonna have

lynda whitehead: you can't even imagine. because every morning i wake up, i think about my daughter and my grandkids. it's just a tragedy. keith morrison: one about a mother who dared dream that her sweet gemini twins would surpass her who instead became their victim. craig melvin: that's all for this edition of dateline. i'm craig melvin. thank you for watching. i'm craig melvin, and this is "dateline." i'm craig melvin, and this is "dateline."my fam. that's in the movies. who would want him dead? someone came here with the intention to murder him. and then i'm thinking, this person is still on the loose, you know? are we safe? craig melvin: she was a southern belle. kris hodge: a little lady, very fun, just someone you could have a good time with. craig melvin: and he was her long-time beau. emily roberts: he adored her and she adored him. craig melvin: united in life, divided by murder. it's just nothing but blue lights. and when you know it ain't good. craig melvin: she was with him that night, found bruised, crying, and