"The moment I saw her, I knew what a beautiful woman she'd become."
Not much is revealed about Bill's early life, other than that he claims to have never felt loved and wanted someone to love, and that he had a fondness for butterflies. Apparently attracted to teenage girls, Bill attempted to abduct a 14-year-old girl by luring her to his studio under the pretense that he would make her a model. When he started making sexual advances, she escaped. It is unspecified if he served any time in prison. The moment Bill first laid eyes on eight-year-old Hope Kingston at a gas station one night in 2004, he instantly became obsessed with her. He thought she was perfect, and he decided that he had to have her, even though she was too young for his liking at the time. Bill followed Hope and her mother Monica to their home in Manassas, Virginia, and after stalking Hope for some time, he used a ruse to abduct Hope from the front yard while she was playing with her friend Heather Wilson. Bill also left a note of thanks on Heather Wilson's bike. Monica frantically put all of her resources into searching for Hope, and as a result, her mortgage took a back seat, and she was forced to move out of the house. Not wanting to move too far away from the home she raised Hope in, Monica moved into an apartment located near the house.
Bill kept Hope in a room on the top floor of one of his two houses for a few years, apparently only allowing her downstairs for meals and special occasions. During the first few years, he had to keep her chained to a chair whenever she was in the kitchen, and then Hope got into her teens, which Bill thought was a more desirable age than she was when he abducted her. Bill started sexually abusing Hope. After many forced years of abuse he got her pregnant, which was most likely the final straw for Hope. As a last resort of freedom from Bill, she committed suicide by slashing her wrists. Before she bled out, she wrote on the wall "Why Me?". Bill tried to help her when he found her on the floor, but it was too late. Her suicide completely derailed his plans for his delusional family. He kept Hope's body on the bed in that room, and it mummified. Bill desperately wanted to recreate what he lost when Hope committed suicide. As part of a deluded plan to "recreate" Hope, Bill entered Garcia's support group, knowing that Monica was in the group, and he began stalking her, without her being aware of it. In group meetings, Bill talked about Hope's suicide, but, in order to cover up the fact that he was talking about Hope, Bill merely said that he had a pregnant wife who killed herself.
In Hope, after spending some time in the group, Bill abducts Monica and initiates his plan: recreate Hope's abduction by taking Monica to the gas station where he first saw Hope, then to the house where Monica and Hope had lived in Manassas, Virginia, and then to the nearby house where he held Hope captive. Bill even plans to get Monica pregnant, like Hope was. Meanwhile, the BAU team, having been persuaded by Garcia to assist in the investigation of Monica's abduction, figure out who abduct her and where Bill is holding Monica: the same house he held Hope in. At the house, Monica makes her way upstairs to the room, and she becomes horrified when she pulls the blanket off the bed and sees Hope's mummified body on the bed. Monica breaks down, devastated that Hope is dead, and enraged at Bill for abducting her seven years ago. Monica then attempts to escape from Bill, who gets rough with her in his attempts to stop her escape. After the BAU and a number of police officers arrive, Garcia talks to Bill on the phone, and Bill, holding Monica at gunpoint, demands that she comes inside to talk to him. JJ accompanies Garcia to the front door so she could talk to Bill, and he isn't aware that JJ is just outside the front door when Garcia goes inside to talk. Meanwhile, Morgan, Reid, and a couple of officers enter through a different part of the house and confront Bill, telling him to put the gun down, while JJ also goes in and tells Bill to listen to them. Bill eventually listens, putting the gun down. However, Monica, enraged and devastated beyond words from learning of her daughter's pregnancy and death, quickly grabs the gun and fires a shot at Bill, which kills him.
Bill abducted all of his known victims using a ruse. After abducting Hope from her backyard, he held her captive in a room on the top floor of his house, apparently only allowing her downstairs for meals and special occasions. During the first years, he had to keep her chained to a chair when she was in the kitchen. When she became a teenager, he began sexually abusing her until she became pregnant. When he abducted Monica, he did it in a parking lot outside the building that had victim's support group meetings and lured her in by saying he knew where Hope was. He intended to do all of the aforementioned activities with her as part of his plan to recreate Hope.
The unsub is a male who was believed to be a preferential offender at the time of Hope Kingston's abduction. However, his preference has now evolved into an erotomanic obsession with Hope. The obsession developed to the point that in her absence, his attentions are now heavily focused on her mother, Monica. At the time Hope went missing, there was another potential victim, who was the same age and shared the same physical characteristics as Hope, and she was even more accessible. This suggests that Hope became his idealized target. Despite the high risk of such an act, he abducted Monica in public, which shows she is very pivotal to his fantasy. It is believed that the unsub has Monica captive within a 20-mile radius of where he abducted her. It is also highly possible that the unsub kept Hope alive until recently, which would explain why he did not hunt for anyone else and that it was Hope's death that triggered the change in his M.O.
The unsub knew that the anniversary of Hope's abduction would be when Monica was exposed and at her most vulnerable. He also knew Monica would be emotionally raw at the support group meeting and may have even heard her tell her story about Hope before, so he may be a member of the support group too. It is possible he initially did not sexually assault Hope but waited until she was older, which would explain why he held her captive for so long. Hope's suicide was never part of his plan and he is not ready to give up the bond he had for her. It would be easy for him to start over, unless Monica could give him what he wants: another Hope.
Bill is largely similar to Wolfgang Přiklopil, the abductor of Natascha Kampusch. Both were adult men who never had a prior relationship with a woman and forced a prepubescent girl into their car, leaving another child as witness, but were not pedophiles. Instead, they held their only victims captive in a room of their home until they reached adulthood, with plans of turning them into their "wives". The captivity ended around ten years later, when Bill's victim committed suicide, and Přiklopil's victim (who had also contemplated suicide) escaped. Both Bill and Přiklopil met and interacted with their victim's mother after abducting their children, unbeknownst to them.
- Unspecified date: Unnamed teenage girl (abducted and presumably intended to rape; she escaped)
- November 13: 2004: Hope Kingston (stalked for an unspecified amount of time; later abducted, held captive for seven years, and sexually abused; committed suicide by slashing her wrists after learning she was pregnant)
- November 14: 2011: Monica Kingston (Hope's mother; stalked for an unspecified amount of time; later abducted, assaulted, raped, and later held at gunpoint; was rescued the next day)
- ↑ It is mentioned that he owned a studio and could pretend that he could make a girl a model, suggesting that he worked as a photographer