>> it's clear that tim arnold and christa had a tumultuous relationship. >> they had an intense relationshipith her for a while. ava started to call him tim mom, so, she wasn't just tim, he was tim mom. >> he's a very sensitive, artistic, educated, well spoken, general gentle person. >> i think one reason christa connected with tim arnold is that he was a literary. he wrote a couple books, he wrote this book "the winter mittens," which is a children's book, but it's a very strange little children's book. it's very dark. >> when she pulled on the right mitten to take it off, it would not move. she pulled frantically at them with her teeth, but the winter mittens held fast to her hands, as if with a life of their own. >> tim arnold and christa would fight. >> tim said that she criticized everything. she would criticize him for humming and she would say she didn't want ava to become a hummer. so, he couldn't even hum. >> they had broken up, but he still seemed to have affection for christa. now, he lived nearby, with his father, only 100 yards away. >> tim told the police that he was out runnin