Would be in a drainage ditch in louisville, kentucky. he said i don t know, but my car was broken into at work last week. reporter: his cadillac. the break-in happened the night of may 17th, a few hours before erin harper was found dead. i asked him, where does he work? a pharmacist at walgreens. bells and whistles go off. he works at a drugstore. there s a reason the manual was with the stuff. reporter: he had a working theory and it went like this. someone broke into a shiny cadillac parked outside an indiana walgreens. it happened to belong to the pharmacist. the thief grabbed the owner s manual and tossed it into his own car. he then went to erin s house where she and erica were shot and erin s prescription pills were stolen. then, according to rick s theory, the person rushed away
Don t catch these people. reporter: at the crime scene, detective arnold was searching for answers, combing the house for more clues. a closet that contains a safe. reporter: contents, apparently missing. the first thing is a robbery. next to that is a cell phone. we check cell phone records. reporter: she received two phone calls in the hours before the shooting, both from a family friend. james had known erin for years. he called her. police brought him in to see if he had any information that could help the investigation. one of the very last people to call her or talk to her by phone, which is why we want to talk to you. me? reporter: he provided names for investigators to check out
that s what i m saying. you were in the house. that s what i want to know about. reporter: how does he react to being cornered, caught in a lie. backtracking. getting scared. i never told you i used to be over all the time. that s what i m saying. reporter: now, he was admitting he visited his friend, erin, that day. he insisted he left before anyone was shot. rick sensed that the story was crumbling, so he went for the jugular, demanding he come clean. and it worked. i saw him go in there and i was behind him. pow, pow, pow. i heard gunshots. him saying he was in that house was critical. that is the most important thing he said. he now had admission number one. the interview near le over, he had a request, one of the
Another death. but, since erica was involved in that, they wasn t going to let up on it. reporter: judith didn t know it, yet, but at police headquarters, detective arnold was close to getting clues. james, the family friend, who made the last phone call to erin and kenneth williams who recollects admitted to a witness that he was part of a robbery that turned deadly. now, it was time to bring both men in and interrogate them. i was apprehensive, but not nervous. no butterflies, just because it s something i had planned on and prepared for for such a long time. reporter: you were ready? i was ready. reporter: 15 months after the shootings, they came to headquarters. each knew the other was there. i wanted them to understand if they didn t tell us the truth, the other guy may be. reporter: as a tactic, he walked williams past a closed
Prescriptions using bogus names. reporter: on the security tape, rick looked closely and saw the man leaning through the window of the enclosed pharmacy section, checking out names from pill bottles. over and over, detective arnold stared at the grainy wall greens tape. the man in the baseball cap looked familiar. as in james, erin s family friend who phoned her minutes before the murder. earlier, he told the detective how much he wanted to help the investigation. find whoever did this. reporter: rick wasn t buying any of it now. he had become a prime suspect, though, rick wasn t ready to arrest him. not yet, not until he had the other man. that wouldn t be easy. there were two suspects in his sights, the mystery man was not in focus. how clear is the image of the second guy? it s not very clear.