According to Hazelwood and Michaud, there was sufficient proof that
Anderson was a sexual sadist who was excited by the physical and psychological suffering and helplessness of his victim. Their opinion was based on four factors:
- Anderson displayed an obvious interest in sexual bondage, a hallmark of the sexual sadist, which was represented by the restraints, dildo, partially burnt candle, eyebolts, handcuff keys, duct tape and plywood platform.
- The evidence found by investigators clearly indicated physical torture. It was surmised that after Piper was abducted, Anderson drove her to a wooded area near Baltic. While there he may have bound her to the platform, gagged her with duct tape, sheared her shirt off and then methodically tortured her with the dildo and candle before raping her. It is believed that he then murdered Piper and disposed of her body.
- Anderson admitted to police and friends that he liked anal sex, a preference his wife did not share. Research conducted by Hazelwood and Michaud found that, sexual sadists prefer this form of sex. They believed that the dildo was used by Anderson to act out his fantasy.
- It was further suggested that sexual sadists habitually plan their crimes in much greater detail than do other criminals.
One of Andersons longtime friends, Jamie Hammer, brought forth evidence, which provided investigators with new information concerning Andersons sexually sadistic and predatory behavior. They learned that Piper was not his only victim. They also realized that he would have likely continued to prey on women, if he hadnt been caught.
During police interviews, Hammer said that as far back as high school he was aware of Andersons obsession with torturing and murdering women. Hammer was intrigued by the idea and the two often discussed ways in which to commit the perfect crime. As their conversations progressed and grew more detailed over time, so did their fantasies. It wasnt long before the two men decided to act them out.
Hammer and Anderson actually planned abducting a woman together. Hazelwood and Michaud stated that the two men got wheel poppers and placed them on the road. They waited for a victim to drive by, run over the poppers and get a flat tire. It was then that they planned to attack the unsuspecting woman. Hammer didnt know it, but Anderson had already pre-selected a victim named Amy Anderson, 26 (no relation to Robert Leroy Anderson).
In November 1994, Amy drove over the wheel poppers on her way home from a friends house near Tea, South Dakota, as Anderson planned. Soon her tire went flat and she pulled off the road to change it. As she reached into her trunk to get a spare tire, Anderson grabbed her and carried her off the road towards a wooded area. Luckily, Amy managed to break free and flag down a passing car that stopped to pick her up.
The attempted kidnapping of Amy remained unsolved until there was a breakthrough in the case two years later. When Anderson was on trial for the abduction of Piper in 1996, Amys case was brought once again to the forefront. She was able to identify Anderson in a police line-up, but he would never stand trial for the crime. At the time, he was already convicted of kidnapping Piper.
Instead, another friend of Andersons named Glen Marcus Walker would take the brunt. As it turned out, he too was involved with Anderson and Hammer in Amys unsuccessful abduction. Several years later during his trial, he pled guilty to the offense. However, it would not be the only crime he would admit that he committed with Anderson. Investigators discovered that several months before Amy was attacked, Anderson and Walker committed another more gruesome crime.
