be extra cautious, lock your doors, lock your windows. pay attention to strangers in your area. reporter: they devoted their lives to others. who would ever want to hurt them? this is just absolutely a despicable act. reporter: for a day that ended so tragically, it began in a happy way with flowers and expressions of love. nathan and denise leuthold had met 30 years earlier, back in the 80s when they were both students at a small baptist school in central illinois. even at that young age, nathan knew there was something to this sparkling little girl. i was in third grade and she was in fourth gade at the time. and i doubt she even knew i existed, but even then i thought she was the cutest girl in the school. what was it that you liked about her so much? it was the curly hair and the bouncy curls and just the happy-go-lucky smile. in junior high i began to see her character and see what kind of person she was that way. reporter: it was in high
the police station the night of the murder, like the fact that he owned three guns. i got a shotgun. well, do you know what .12 gauge. okay, what else you got? i have a .22 silver with pearl handle, little. and then i have my primary one, which is a glock. what model? model? i know it s a .40. reporter: there were a lot of things about nathan s guns that didn t add up for police. starting with the fact that he happened to own the same type of gun used in denise s murder. how did he explain that? he couldn t. i think he was trying to allude to the fact that the burglar must have got into it and taken it. yeah. reporter: nathan also told police he kept that gun in a plastic case. and you kept it locked? yeah. how hard would it be for somebody to pry it open? would you need like a crow bar or something? no. reporter: but, there was no broken case at the house. that said a lot to the detectives. and then i asked him, where is the box? he said he didn
anything. so when she entered that door that shot was immediate. reporter: and the weapon appeared to be a .40 caliber handgun. but no sign of the gun. did it seem like denise had possibly startled a burglar? yeah, it looked like she interrupted a burglary that she came home. the house had been ransacked like somebody d broken in through the back door, started going through the house and then maybe startled the burglar when she came in through the front door. reporter: while investigators combed the crime scene, nathan anxiously watched the police activity from the house across the street. how did they tell you what they had found? the police were not the first people to tell me. unfortunately, i found out about it from my father. i was calling my dad and dad said, well, i m on my way. i just heard on the radio. the local news media just put on the
did you feel like we have a mystery on our hands. we ve got to solve this. yeah, we knew we had we knew we had something bad. and we knew that it was gonna take a lot of work to get to the point where we knew who done it. a possible clue? nathan remembers seeing a suspicious car near his house not long before the murder. this is kind of weird, pulling in the driveway i normally go through in by the front door and turn the outside lights on. was the killer in that car? when dateline continues. and active probiotics. make the most of this holiday season by supporting your gut health.
killed in her parents home where she and her family had been living. typical scenario? robberies happening in peoria? this one just happens to be a lot worse? it s not typical as far as a burglary that results in a murder. that doesn t happen very often. reporter: this was an odd one. detectives needed to know more about denise and began questioning her family, including nathan, her husband of 17 years. you talking to us and cooperating with us is the best information that we can get. we want to talk to the people closest to her first to try to figure out what makes her tick, what s her routine like. did you start to think that someone may have targeted denise? well, you know, we didn t know. i mean you know, nathan he s gonna be our best witness. you know, you re livin with this lady and you ve been married for a long time. you know her routine. did you think maybe someone had a reason to be in that house, outside of just a random burglary? we didn t know.