foulston: he was really prolific. he used to take photographs of himself.on. it was despicable, disgusting, sexually bereft-type of stuff that you have never seen in your life and you don't ever want to see again. and that was all involved with that case. in our minds, as this was discussed and kind of profiled down at the behavioral science unit, was really his art. and he does a lot in what we call the expressive style. he really likes that. o'connor: he actually entered pleas of guilty to the 10 homicides, and so judge waller had rader describe the murders at his guilty plea, and i believe dennis rader was more than happy to describe what he had done. man: when you went into the house, what happened then? well, i confronted the family. i pulled the pistol, confronted mr. otero. otero: that day we went to court, and we listened to the testimony about how my family was killed. it was very, very hard. i didn't have a mask on or anything. they already could i.d. me. it was once again that feeling of my chest being ripped open, had come back to me. and made a

foulston: four people getting killed at home with two young children.the dark side and to do this kind of thing. january 15, 1974, wichita instantly changed. it wasn't an innocent city anymore. it became a city that was afraid. ♪ relph: law enforcement at the time were looking at it as, "is this a one-off? what is this?" there was just no reason to slaughter this family. otero: from what i understand, the police were wondering if my father's activities overseas had anything to do with their demise and what had happened to him, so there was a lot of questions about overseas contacts. hatteberg: as the days progressed, our police reporters were all over it, trying to get information. i remember the police chief checking on that somehow that this could be related to drugs, but it wasn't. so they abandoned that lead. singular: they put 75 officers on the case. they contacted other police departments. they interrogated 800 people in the first few weeks of it. they set up roadblocks and were stopping all kinds of people, and they came up empty on everything.