were soggy to the point when i started to look through the very first time and flip through, pages are still sticking to the. reporter: days later, rick would separate a few pages but was still frustrated. it was the third time. i really was thinking, you know, this is if i don t find something, i went through this and licked my thumb and forefinger and went through it page-by-page. reporter: the third time was the charm. i was able to find stuck in the binding an automobile insurance card with a name. reporter: with a name? a name, most importantly. reporter: his working days had turned into working nights. detective arnold typed a man s name into his computer and special spit out 15 matches and one lived in southern indiana across the river from louisville. around 11:00 p.m., rick called the man. i asked him if he knows why mi hanel would be in a drainage ditch in louisville, kentucky? reporter: what did he tell you? he said i don t know but my
car was broken into at work last week. reporter: his cadillac, the break-in happened on may 17thth, a few hours off erin harper was found dead. reporter: i asked him where do you work? he said he was a pharmacist at a drugstore where she sell prescription drugs. it hit me the manual was with the stuff now. reporter: detective arnold had a working theory and it went like this. someone broke into a shiny cadillac parked outside of an indiana walgreens. the car happened to belong to the store s pharmacist. the thief grabbed the owner manual and tossed it into his own car and went to erin s house where she and erika were shot and erin s prescription ills pills and credit cards were stolen and according to rick s theory the person rushed away from the house, threw the pill bottles and credit cards into
maybe another death but because erika was involved in, that they wouldn t let up on it. reporter: down at the police headquarters detective arnold was close to getting answers to the man he was pursuing since the walgreens video was found. james quisenberry and kenneth williams who admitted he was part of a robbery that turned deadly. now it was time to bring both men in and interrogate them. i m a little apperehensive bt i was ready. reporter: 15 months after the shootings, quisenberry and williams voluntarily came down to headquarters. each knew the other was there. i wanted them to understand if one guy didn t tell us, the other would. reporter: he walked past the