Robert and Linda targeted blonde, blue-eyed, troubled runaways aged between 16 to 19 years old. Robert would abduct them personally (since Linda's disease kept her at their home) from different cities in New Mexico, and take them to his and Linda's home in Arizona. He would usually hold two at a time, put them in a dungeon in his basement, and bind them by their wrists and ankles using chains. He would sexually assault and impregnate them while holding them captive until they gave birth. Before impregnating his victims, Robert and Linda would get them healthy enough to carry a child and also give them various medications to make the birthing easier. When the births took place, the most recently abducted girls would act as midwives.
If the victims gave birth to a girl, they would be killed by asphyxiation and dumped near highways in New Mexico. The daughters were then left on the steps of a nearby Presbyterian church to be put up for adoption or in foster care because they wouldn't think to look for the babies' relatives out of the state. If they gave birth to a boy, the victims would stay captive and Robert and Linda would take the newborn and raise it as their own; the victims would also act as nurses when necessary.
The unsubs responsible for the abductions and murders are most likely a couple aged in their 30s to early 40s. The husband would have a history of sexual abuse, starting with stalking and then moving up to assault and rape, but this violent streak had ended temporarily when he met his wife, to which he became calm, having met someone who submitted to his torture. His wife will have gone to the E.R. repeatedly with signs of spousal abuse sometime in the past five years, prior to the first abduction. However, since a sexual sadist cannot derive any pleasure from a willing partner for long, and the husband could not escalate his violence against her without killing her, the wife made a deal with him: he would get to rape and kill the runaway victims in exchange for her keeping the children and taking care of them as an outlet to cling onto her own life.
The medications that are being given to the victims suggests that the wife may have some obstetric job, such as a nurse or an O.B. The wife needs these children, which were the only lifeline that kept her alive, and as long as her husband had other targets for his abuse, she avoided his rage. She also wants a child who resembles her and her husband physically, a child whom no one would question as their own, which is why she gives some of them up for adoption. All of the runways were blonde, which may mean the wife is as well. Whatever the desirable physical characteristic, like the color of the eyes or the skin type, if the baby doesn't have it, he or she ends up being placed in the foster care system. Wives of sexual sadists need outlets as a denial mechanism to cope with what their partners are doing to them, and motherhood, especially in which a helpless infant is taken care of, is the wife's way of coping.
The dates denote when and where the victims were abducted
- New Mexico:
- October 2004, Lovington: Monica Winmar (abducted and raped repeatedly; killed on March 24, 2006, shortly after giving birth to a girl)
- July 2005, unspecified location: Janeen Atterman (abducted and raped repeatedly; killed on April 1, 2008)
- December 2006, Farmington: Kristie Taylor (abducted and raped repeatedly; killed on October 19, 2009, shortly after giving birth to a girl)
- March 2008, unspecified location: Carol (abducted and raped repeatedly; was rescued on October 21, 2009, shortly after giving birth to a boy)
- October 20, 2009, Albuquerque: Julie (non-fatally suffocated with a plastic bag and abducted, but not raped; was rescued the next day alongside Carol)