Forgetting Cooper News Today

>> right. >> reporter: -- ten minutes before he left with cooper? >> right. we were able to determine that he had been messaging at least six different women throughout that day, sending pictures of himself, asking for photographs. >> reporter: prosecutors believed ross harris was in the grip of an escalating obsession with sex. and they came to an awful conclusion. that ross wanted so badly to be rid of the constraints of family and fatherhood, he decided to kill his own child. does being a cre...

And a double life. >> reporter: chuck boring, the lead prosecutor, told the jury why ross story had never added up. that chick-fil-a video showed cooper wide awake. that drive that was too short to forget a toddler. the car seat was just inches behind ross. and at ross office there was a photo of cooper and a gift from cooper. he even sent a text to leanna in the afternoon about cooper. when you getting my buddy, it said. none of that jogged his memory? >> there was just cue after cue after cue ...

>> theres his toys, his pictures. its not real if she doesnt go inside. >> reporter: katie says leanna was numb without her child and her husband. did she go through that emotion at any point, im angry at you? how could you do this? >> i dont know that she was ever angry at him. >> reporter: because you go through that scenario as a parent, what if my spouse did this? would i be able to understand? >> but shes such a composed woman. and her faith, i dont think, would let her be angry at him for ...

>> reporter: but what about a those reminders during the day? shouldnt one of those have triggered his mind to say, wait. cooper. wheres cooper? >> i think thats a fair question to ask. if ross had forgotten that he had a son, seeing a picture of cooper would have reminded him that he had a son. he didnt forget he had a son. once ross slipped into his work day, he had every reason to believe that cooper was at the day care. >> reporter: as for those witnesses who said ross seemed detached, they ...

>> he said it while he was talking to leanna that, you know, he was dreading how cooper was going to look when he got him out. >> reporter: almost like -- >> he knew what was there. exactly. he knew what was going to be found. >> reporter: they were also struck by how calm leanna seemed to be. and by this surprising question. >> did you say too much? >> reporter: detectives wondered what she meant. they came back into the room and told ross he wasnt going home. >> hes going to jail. hes being ch...

Home. >> we had sex. >> reporter: and a prostitute. >> did you actually engage in sexual acts with him back in may of -- >> yes, on three different occasions. >> reporter: this witness is one of the six women ross was communicating with the day he says he forgot about cooper. >> and at 5:46 a.m., within 17 seconds of your messages, did he respond? >> he did. >> reporter: did you have to consider the fact that maybe all these women were causing a distraction for ross, which then led to what happe...

There he is getting picked up. but look here, nearly an hour later, there he is again getting dropped off at his car. he opens the drivers door and throws a box of light bulbs onto the front seat. ross never told detectives about going back to his car in the middle of the day. did he lie about going to the car or did he just not disclose that he had gone to the car? >> i think when you look at it in totality, he absolutely lied about it. >> reporter: investigators were sure ross was hiding somet...

Was, she stuck it out for nearly two days of testimony. >> that woman had every reason in the world to hate ross harris. and despite all of that, despite all of that, she was willing to come testify for him because she knew what the truth was. >> reporter: and then, in his final question to leanna, ross attorney wanted to make something clear. leanna was there for one reason only -- she believed that what happened to cooper was a mistake, not a crime. and now she was ready to walk away. >> how d...

>> reporter: what were talking about here, there is actually a name for this. >> this is referred to as forgotten baby syndrome, which actually describes a phenomenon in which normal, attentive and loving parents, for reasons we dont fully understand, lose awareness that their child is in a car. >> reporter: diamond says it can happen to anyone. distraction and exhaustion often play a role. he add, once the child is forgotten, the brain plays a dangerous trick. >> whats remarkable about these ca...

Accidentally left cooper at home. >> she texted her neighbor and asked her to just go look. she has a key to her apartment. just go look. see if hes there. and she was like, maybe the house will just be torn up. it had be a little toddler tornado when she gets there, but hell be there. obviously, he wasnt. >> reporter: leanna rushed over to ross office to see if cooper was there. it was at home depot that a police officer tracked her down. their conversation was recorded as he gave her the worst...