|“||I think I said watch it. I said watch it!||”|
— Sheppard to one of his hostages
Sheppard's father died from unknown causes when he was young. After that, he and his sister were left alone with their mother, a painkiller addict, whose inebriation and loneliness caused her to abuse them, possibly sexually. Eventually, in 1994, Sheppard's sister killed herself. This drove him to start acting out, spending the next 12 years in and out of juvenile detention facilities and prisons for various crimes. In the 90s, he served time in the San Luis Obispo County Jail, at which a pilot program for psychodramas was performed at the time. When he was there, he was presumably subjected to that form of therapy and was also taught how to rob banks by other inmates. Before the episode, he somehow acquired a MAC-10 machine pistol and used it to commit three bank robberies in Los Angeles. He would force people at gunpoint to strip down to their underwear in order to make them less likely to fight back or chase after him, lock their clothes in the vault, and take the money. During his fourth robbery, however, his crystal meth addiction had caused him to spiral out of control and the memories of the psychodrama therapy were provoked into returning. He forced two couples at gunpoint to simulate sex with each other and beat a uniformed security guard to the brink of unconsciousness.
As the BAU's investigation proceed, Sheppard becomes less careful and continues spiraling. At his fifth bank robbery, he doesn't bother checking all rooms (subsequently missing a hiding customer who calls 911 in the restroom), parks his motorcycle illegally, and beats a bank deliveryman to death when he refuses to take off his clothes. He then flees when he caught the hiding customer calling 911, and later punches a ticket lady in the face outside while getting to his motorcycle. Escaping the BAU after a short chase, Sheppard arrives at a small restaurant, fires his gun into the air, and forces a teenage boy to slap his mother in the face. When he refuses to hit her harder, he shoves him to the floor and shoots him repeatedly, killing him instantly. After that, he holds the attendants of a birthday party near the motel he was staying at hostage, gives his gun to a young boy, and holds a knife to his throat, instructing him to shoot his own mother. In the process, he projects his mother's image onto the woman. By then, the BAU has identified him and tracks him down at the party. They attempt to get Sheppard to surrender, but when that isn't possible, Hotch, enraged over his actions, shoots him in the shoulder, making his arrest possible. When Sheppard demands drugs to help combat the pain of his gunshot injury, Hotch tells the medics not to give him any because he had shot and killed a teenager earlier. Sheppard is presumably incarcerated or possibly even institutionalized afterwards.
"I got a mac-10. One shot. You got one shot to kill me. Even if you kill me, I'm going down shooting."
Sheppard's initial bank robberies were skillfully planned. Prior to committing them, he would visit the banks beforehand to see which times there were the most customers, memorize the layout, and see where all the employees would be. During the actual robberies, he would enter wearing a black ski-mask and lifts inside his shoes to obscure his real height to the authorities, fire his MAC-10 machine pistol at the ceiling, clear the rooms, talk down eventual security guards, and force bystanders to strip down to their underwear (in order to make them less likely to chase after him or fight back). He would then place their clothes in the bank's vault, take the money, and flee on a motorbike.
During his fourth robbery, however, he beat the bank's security guard to the point of near-unconsciousness after handcuffing him to a table. He then placed the stripped bystanders in the middle of the bank (where they could easily be viewed by people outside) and made two pairs of victims simulate sex with each other. During his fifth robbery, he forgot to clear all the rooms, struck when more people were present, and beat a man to death with his MAC-10 when he refused to undress. Sheppard's sixth attack was committed in a restaurant, at which he forced a teenage boy to hit his mother and repeatedly shot him to death when he refused to continue. His seventh attack was committed at a birthday party, during which he tried to get a young boy (held at knifepoint) to shoot his mother with the MAC-10.
"They're gonna have to learn sooner or later."
"What are they going to have to learn?"
"That no one's there for you."
-Sheppard and Hotch
Based on the knowledge that spending a significant time in prison stunts emotional growth while increasing professional skills, the unsub is estimated to have spent five to ten years in prison and have been 18-23 years old at the time of his initial incarceration, which would put his present age at 23-35. He is much more than a bank robber, though. What started out as a practical M.O., which was formed for practical reasons, triggered a deep psychological response and made it compulsive for him to manipulate bystanders. That urge is getting worse, since he is attacking banks earlier in the day when more and more people are present, indicating that he sacrifices safety of having just a few hostages to contain for the satisfaction of having more subjects to control. He would be less interested in the money and more interested in sadistically manipulating his captives. It is likely that he is high on drugs during the robberies, but it is wrong to write him off as "crazy", since robbing banks is an ambitious crime that takes time and planning to pull off. What makes him unique from the other bank robbers is his fractured psyche: on one hand, he is a cold, organized bank robber; on the other, he is a disorganized sexual sadist, full of bottled-up rage. The two parts of his psyche have just begun to blend together, and when they finally converge, he will have the skill and efficiency of a master bank robber and the rage of a suicide bomber.
He was, at first, believed to be a sexual sadist who forced his victims to simulate sex for the humiliation, but the truth is that he was forcing the victims to perform psychodramas, a form of psychotherapy in which actors serve as surrogates for people in the subject's life. His fantasies were usually about sons exacting revenge on their mothers.
Sheppard may have been based on a bank robbery case in Grand Rapids, Michigan, mentioned in John Douglas's book Crime Classification Manual. Like Caleb, the perpetrator forced bystanders to undress completely before taking the money.
He also might have been partially inspired by Larry Phillips, Jr. and Emil Mătăsăreanu, a pair of bank robbers - Both were bank robbers and killers who committed a series of notorious bank robberies in the Los Angeles area, using an automatic firearm that they would fire into the ceiling in order to intimidate bystanders. During one of the robberies, his murder of a deliveryman, a bank employee, seems to be an obscure reference to the murder of security guard Herman Cook. They were also given nicknames for their crimes, and all their crimes ended in a standoff with Police (though only Sheppard emerged alive).
- Unspecified dates in c.1994-2006: Numerous unspecified crimes which landed him in-and-out of jail
- August: A victimless bank robbery
- August-October: Two victimless bank robberies
- October 9: The fourth bank robbery:
- An unnamed security guard (assaulted; beaten nearly to unconsciousness)
- An unnamed man (assaulted)
- Bill and Claire Henderson (the bank manager and his wife, respectively; forced at gunpoint to simulate sex in front of their children)
- An unnamed elderly woman and an unnamed young man (also forced to simulate sex at gunpoint)
- October 11:
- The fifth bank robbery:
- An unnamed woman (threatened to shoot)
- An unnamed male deliveryman (was beaten to death with his MAC-10)
- An unnamed man (intended to shoot, but relented at the last second)
- Unnamed ticket lady (assaulted; was punched in the face outside of the bank)
- The restaurant shooting:
- Numerous unnamed patrons and employees (all held hostage)
- An unnamed woman (forced her son to assault her)
- The woman's unnamed teenage son (was shot repeatedly)
- The birthday party standoff:
- Numerous unnamed parents and children (held hostage)
- Jeffrey (held at knifepoint)
- Jeffrey's unnamed mother (attempted to force Jeffrey to shoot her)
- The fifth bank robbery:
- Jason Wiles, the actor who portrays Sheppard later makes a second appearance on Criminal Minds, playing a different role in the Season Five episode "The Fight", in which he plays Ben McBride, a survivor of the featured unsub.
- The MAC-10 used in the episode is actually a Non-Gun replica modeled after the machine pistol. This is another example of Non-Guns in the show. Another example in the show are the Glocks used. One may notice (including in this episode) instances of a character firing a Glock, yet the slide doesn't move and no shell case is ejected.