rich arnold: this is detective rick arnold. today's date is may 18, 2006. hoda kotb: a video camera rolled as detective arnold processed the crime scene, homing in on clues. rich arnold: on this drum near the victim's body, it's a shell casing. hoda kotb: the harsh reality of death lay side by side with the everyday images of young life. earon's body in a pool of blood near a red kiddie wagon, a shell casing in front of a box of diapers. and the bed where erica once jumped for joy, was now covered in her own blood. rich arnold: and suspected blood on the sheets, the pillows and the pillow cases. hoda kotb: detective arnold noticed something on the bed that would burn in his memory throughout the investigation. the first thing that immediately hit me was the dora the explorer pillow. and it had blood on it. what was the emotion when you saw that? anger. hoda kotb: with two young kids of his own, this case had already hit rick arnold hard. on the spot, he made a promise to erica's grandmother. you said we're going to find who did this. yes. that's a lot to pro