reporter: that loving relationship is just one reason that all that happens next, seems so unbelievable to leannane 18th, 2014, the day that would forever change your life. it was a day like so many others. ross was in charge of dropping cooper off at day care in the morning, and leanna would plan pick him up in the afternoon. it was typical in one other way. it's a june afternoon in atlanta. temperature, 91 degrees. >> i left work probably around 4:00. i had about an hour drive. i got to the day care. and walked in just like i would any other day. >> reporter: security cameras capture leanna from the moment she arrives. >> the day care teacher that was there, she said, "what are you doing here?" and i said, "i'm here to get cooper." and she just kind of looked at me. she said, "well, cooper's not here." and i thought she was joking. "no, really, where's cooper?" and she -- she just -- she looked me dead in the face and got my attention. she was like, "he's not here." >> reporter: what did you think? >> i didn't know what to think. it didn't make any sense. >> reporter: were you scared? >> absolu