>> he had the right drugs, drugs that were fast acting, that caused amnesia, that relax the victims enough, that's the intention of them. >> that would explain some of the things that were done to me. being tied down and how uncomfortable you're going to feel and being used as a sex slave. >> ray released kelly after three days, confident that the potent drugs would erase her dark memories. >> it was very risky behavior on his part. he felt confident even though he did let them go, they would not remember the incident. that's in fact true. >> coming up, police become convinced they have a serial killer on their hands. >> i won't have any qualms at all about slicing your throat. >> if you believe what david says on the tape is true, that he rapes and tortures women, there's no reason not to believe the other parts about killing women and disposing of their bodies is also true.