Dateline | January 31, 2014
>> reporter: answer to that question would be the responsibility of the investigators, the indiana state police and the floyd county prosecutor in southern indiana , stan faith. he got the call at 10:00 , 10:30 that night.
>> did someone on the other end of the phone tell you it was bad?
>> narrator: faith knew immediately the case would be big. he got to the crime scene asap. the first thing the prosecutor noticed was the ribbon of blood running out of the garage downing the drive. she could see kim lying by the passenger door, her pants removed. it had the signature of a sex crime , the children killed because they were witnesses. an article of clothing that would become hugely important in time.
>> the boy was laying there and his hands were out and of course i didn't see the little girl . they told me that she was still in the truck.
>> narrator: the state police , indiana's top investigative force had all right begun its work. the crime scene techs examined the bronco, took their measurements and their pictures.
>> was it too soon for you to take all that stuff in?
>> the thing that struck me the most was how clean the garage was. you just don't expect that.
>> narrator: some of the troopers in the garage had been fellow officers of the husband, david camm .
>> there were a couple they didn't really recognize, but for the most part, throughout the course of the evening, tlltd here would be people that i knew.
>> narrator: the chief investigator would be david 's childhood friend . they would have the talk right there.
>> he said i know, get it done.
>> because of your experience, they always look at the spouse.
>> sure, everybody's a suspect. in the beginning, you don't know.
>> narrator: but in his case, david thought, it was a by the book formality. he was confident his friends would do all they could to find the killer.
>> these were your brothers in uniform, these guys?
>> you had ridden with them.
>> they had been to my house, we had eaten together, we knew each other's families.
>> narrator: in this audiotape of his first interview that night. you can hear the troopers handling him with kid gloves out of respect.
>> we're going to try to find out what happened so that we can bring that person to justice as best we know how.
>> get it right.
>> right, exactly.
>> whatever you want to ask me.
>> narrator: as far as david knew, his wife had followed her usual busy routine, working and then shuffling the kids around after school. was the shooter waiting for her in the garage? or did her killer follow her in? the investigators asked david if anyone had been stalking kim , bothering her?
>> if there was, she hadn't said a word.
>> how about phone calls ? any hang up phone calls ? suspicious phone calls ?
>> narrator: and they wanted to know if the husband could help them understand and oddity about the crime scene . why would kim 's shoes have ended up neatly placed atop the roof of the bronco.
>> i have no idea why her shoes were up there.
>> did she ever kick her u shoes off while she's driving?
>> never seen her take her shoes off. never.
>> you saw those shoes, though?
>> damn straight i did.
>> narrator: as the investigators wrapped up, they made sure that david got fresh clothing because they were sending they shoes and t-shirt out for testing. the next day the camm's neighbors were absolutely stunned by a crime of this magnitude in their quiet community.
>> it makes no sense. there's never been any trouble out here to speak of, you know.
>> narrator: as the hunt for the killer continued, investigators asked neighbors if they had seen or heard anything suspicious?
>> right now, this is very, very much an open investigation.
>> narrator: three days after the murderers, david camm faced the cameras.
>> i want my family back, i want my babies back and my wife.
>> narrator: and he begged the killer to come forward.
>> turn yourself in, you can't live with the guilt. what you did was such air rational ridiculous, ludicrous, satanic thing. you cannot -- you cannot live with that guilt.
>> narrator: an arrest in the case was only hours away.