this is detective rick arnold. today s day is may 18th, 2006. reporter: a video camera rolled as detective arnold processed the crime scene honing in on clues. this drew the victim s body, the shell casing. reporter: the hard reality of death lay alside-by-side with t everyday images of young life. aaron s body in a pool of blood near af red kitty wagon, a she casing in front of a box of diapers, and the bed where erika once jumped for joy was now covered in her own blood. the blood on the sheets. the pillow and pillowcases. reporter: detective arnold noticed r something on the bed that wouldon burn through his memory throughout theur investigation. the first thing that immediately meet was the dora explorer pillow and it will blood on it. reporter: what was the w emotion when you saw that?