and she pulled up a picture of the check and it said, "to isaiah hagan for groceries." being halee, she told friends she'd forgiven isaiah after he promised to pay her back. >> if you want to take a seat over there. >> sure. >> three days after halee's death, police decided it was time to talk to isaiah themselves. >> he sat there in this chair and i sat here. >> what was his demeanor like? this is a -- this is a big case. this is a young guy. >> almost surprisingly calm. just very, very quiet. and didn't show much emotion at all. >> isaiah told investigators the same story he'd told jake. he'd picked halee up at her apartment and then dropped her off at that local park. >> and she's, like, "you can go if you want to, " and i was, like, "are you sure? like, is everything okay. she's said, yeah, everything's fine. >> what isaiah didn't know was that more than a dozen investigators were watching his interview remotely from the next room. and they had proof he was lying. they'd checked the park's security cameras and there was no trace of isaiah and halee. cellphone data sh