back to dateline. in corvallis, oregon-- >> nearly two weeks after brooke wilberger disappeared afterrvallis, oregon. >> search teams spent a days surveying acres of land. >> the search was winding down. the official and would soon come. members of brooks family expressed their gratitude. >> you've given up so much to help, and i was thinking yesterday that brooke will be saying they didn't even know me. >> while detectives were still looking at sung koo kim as a person of interest, at least one of brooks siblings took one look and thought no way. >> we never once for a second thought he had anything to do with it. i personally didn't because i just kept thinking, she could get away from him. he didn't look very threatening to me. >> soon, more reasons surfaced to cast doubt on the idea that kim was involved in brooke's disappearance. >> he offers an alibi. >> offering an alibi and us being able to validate that alibi are two different things. >> but kim's alibi for the day of brooke's disappearance consisted of not just one, but three pieces of evidence. put together, they showed kim