otherwise careful killer. but who would want to hurt her? and so horribly? the first person detective ellzey talked to was shelley s roommate, ashley olvera, who d found shelley dead in her own bed. that s how ashley became possible suspect number one. she wasn t sexually assaulted, shelley. that was my initial opinion. it was later confirmed. reporter: yeah. why couldn t a woman do this? reporter: sure. it s her roommate. there s a lot of things happen between roommates that we don t know about. so it very well could have been. reporter: sure. what happened, if anything, between these roommates was something detective ellzey was determined to find out. even if he had to get rough. coming up. right away, he would become convinced that something just wasn t right between the two girls. what else can you say? it s weird. it s not natural. it s not normal.
don t call me a damn liar! i just talked to her mom her mama, shelley told her mama that ya ll had had nothing in common. and that it was over. that it was through. [ shakes head ] she never said that. boy, you sound like mad. you re a damn psychopath. are you like coo-coo-coo and la la land? does [ expletive ] not register to you? nothing makes sense. i m just i m just waiting to wake up. that s right you re waiting to wake up. now what did you do with the knife? i wasn t there. nathan, you i didn t do anything with a knife. yeah, you did. reporter: detective ellzey made no apology for the aggressive tone of his interrogation. there was more to learn about this closed off young man, for whom questions about knives would have an extra special meaning. reporter: coming up
and i didn t see him for the rest of the day. reporter: in a murder so up close and personal so vicious boyfriend nathan naturally became a person of interest immediately. when officers brought him to dallas police headquarters, detective ellzey was more than ready to ask nathan some very personal and specific questions about his relationship with shelley. are you a virgin? yeah. is shelley a virgin to your knowledge? y all ever discuss sexual intercourse? never? she s been in your bedroom before with the light off. what do ya ll do? we were sitting there playing video games. you never tried anything sexual with her? [ shakes head ] she never tried anything sexual with you? did you kiss her? no, never. you never kissed her? she s been your girlfriend two months and you never kissed her? [ shakes head ] cop: why? it s weird.
it was my first girlfriend. reporter: detective ellzey had never heard of a college romantic relationship like that. question was, could he believe it? how many 19 and 20 year old people proclaim to have a girlfriend or boyfriend who have not kissed them? reporter: nathan also said he hadn t seen or spoken with shelley since several days before the murder. in fact, he said, he spent much of the week back home with his mom and grandmother. was he telling the truth? standard procedure detective ellzey checked out nathan s body for scratches. all right, turn around okay turn back around again. how did you get those scrapes? right here, them scratches? oh, i actually, i scratch myself. reporter: again, could he believe that? we asked him, can we go to your apartment? you know? describe your apartment. do you have knives? do you have swords? do you have this?
horrific. reporter: that sight sticks with you. yes. very much so. reporter: murder, as detective ellzey knew from long experience, takes something from the investigators, too. makes them hard sometimes. but when he learned about the victim, about her decent family, her quiet modest life, her innocence, the murder of shelley nance hit him personally. i mean that was doin nothin wrong. she was not in the wrong place at the wrong time. she was not associatin with somebody that she shouldn t been associated with. the stars lined up just right that somebody, an animal, decided to take her life. reporter: sounds like it got to you, this one? well, you know, i ve got two daughters. and yeah, it s it s hard. reporter: shelley died here, in the falls , a large housing complex where the art institute arranged for some of its