so we're 23 minutes in, and we are making the turn on to sauvie island. >>> sauvie island, oregon.e not far from bustling downtown portland and yet it's a world away. a bocolic area of pumpkin patches, waterways and beaches, sauvie island also features thousands of acres of undeveloped wildlife preserve. authorities have been searching here for months, as recently as this fall, reportedly because terri horman's cell phone can be traced to sauvie island on the day kyron went missing. former prosecutor jim mcintyre. what possible reason could terri horman have for driving to that island? >> one argument would be because she had a small child that was sick and it's wide open. she can drive around and just kill the time. one other speculation is, if she was involved with anything with kyron, that would be an area that some people would think where she could be disposing of kyron. >> do something terrible and no one would see her. >> it's an area that a lot of people would think that was a good place to get that done if you knew the island and where to go. >> but the theory that terri h

reporter: it's been more than a month now since officials and volunteers on horseback scoured sauvy island evidence. and the search seems exhaustive. investigators still have not found the one clue that might crack the case. >> this is not a homicide. it's not a kidnapping for hire that we know of or ransom. and the fact is, there's not even a discernible crime scene. >> reporter: the latest search comes after kaine horman asked the judge to punish teri horman if she doesn't answer questions. she was the last person known to have seen kyron alive. he says she has information concerning kyron's whereabouts and she won't answer because it will lead to criminal liability. >> no judge is going to force her to testify. she is entitled like any other citizen to maintain her silence. >> reporter: the two are locked in a bitter battle. early ther month, ter -- this month, she withdrew time with her 2-year-old, after kaine questioned her fitness as a parent and mental state. >> reporter: attorneys say kaine horman is using the divorce to vilify her. >>> the search for a newborn found abandoned at a

paid workers and volunteers scoured an area called sauvie island, not car from kyron's home. >> reportere island has been an intense focus of dive teams and search crews many times before in this case. so why search again now? investigators say they don't have any new leads but rather, believe that changing weather conditions could turn up evidence that may have been invisible just a few short months ago. >> when you have water levels that are changing, there's some idea that if kyron or some other evidence has been lurking on the bottom of that muddy flat all summer it may actually get dislodged. >> reporter: while police have never named a suspect, kyron's father has only intensified his own very public suspicions that his wife, terry horman, kyron's step mother, is involved. in court filings just last week, cane horman's attorney writes, one can only infer that mother will not speak because her testimony will lead to criminal liability for kyron's disappearance. until mother denies the allegation, there can be no other inferences drawn. despite bold accusations, fresh searching, and n