>> my name's lukah chang. >> i'm gonna write it down. what's your last name? >> chang.ure enough, not danny wu, lukah chang. 23 years old, the son of christian missionaries. a deserter from the u.s marines who drifted into town without any plan and stayed briefly at that downtown motel where he encountered a maid named amyjane. >> did you talk to her? >> no, only in passing. like, she would knock on doors and say, "hey, you want your room cleaned?" like, no. >> reporter: soon chang was broke, living on the street, spending his days at the town library across the street from the travelodge. >> so, you walked by and you saw her? >> i saw her working and it's, oh, look, a target of opportunity. attack. >> so, i just walked in and waited. >> okay. >> how long did you have to wait? >> probably half an hour. >> as you're waiting there a half hour, you're thinking to yourself, what? >> i'm gonna do it. >> so, you grabbed her, brought her into the motel room, the bathroom and then what happened? >> i stabbed her. >> with what? >> a knife. >> reporter: but when detective jackson

as a missionary's son, was lukah chang rebelling against his parents? against god?uestion on just about every mind in pendleton, oregon. >> why? >> see how it felt. >> see how what felt? >> taking a life. >> why? >> i was curious. >> how did it feel? >> empowering, saddening. >> empowering and saddening at the same time? >> uh huh, yes. empowering because i took a life. saddening because i realized at the same time, life is precious. >> reporter: that was it? to see how it felt?? >> i didn't understand that. i've never head that from a killer before. >> reporter: but why the second attack? did he target those two women because they taught bible school together? because they appeared in that photograph together? >> not really. it was approaching the anniversary of the first time. >> reporter: and that was just about it, said lukah chang. >> she was walking by. i noticed, followed, attacked. >> reporter: he was a brick wall. if the real answer was buried in his religious past, or his failed military career. or some other secret corner we were not to know, ever. >> you