>> what are those searches like? >> they're -- they're rough. you never know what you're going to come across. i now can understand the difference between human bones and animal bones. still scares the hell out of you. >> christina's boyfriend hunter told police he was in dallas with friends the night she disappeared but he'd been stingy with the details. he had erased conversations on his phone between himself and christina. investigators were also trying to check enrique's story -- that he was alone when he drove out of the garage early that saturday morning. >> so you -- you know what we're working on, right? what we're trying to is a -- and you're being very helpful with -- >> yeah. >> is being able to figure out, you know, the last place she's seen. because that way we can focus our efforts -- >> right. >> -- searching in this area. >> though his memory seemed fuzzy, enrique had been cooperative, speaking with detectives down at headquarters without an attorney. and police found no trace of