"Wait till you see this."
Bates was born in Carson City, Nevada, and was presumably a pyromaniac all his life. When he was twelve, he set the family home on fire with his older sister Trisha locked inside, apparently intent on killing her, but that failed. He attempted to kill his sister a second time two years later, again without success, he was sent away to a foster home by his parents, who were concerned for Trisha's safety. As he grew up, Bates managed to live a normal life and kept his psychopathy and pyromania closeted secrets. Because of his attraction to fire, he found a job at a repair company that specialized in pyrotechnics, which allowed him a near-constant exposure to open flames. At some point in his life (presumably his childhood), Bates suffered an accident in which his arms were scarred by flames.
In 2014, Bates managed to find Trisha's current residence in Los Angeles, California. He emailed her in an attempt at reconciliation, but she sent him a verbally abusive response while rejecting him and then deleted her account shortly after. This latest rejection sent Bates over the edge, and he traveled southward to San Diego. There, he killed a teenage girl named Lisa Ruiz, who had a younger brother and therefore reminded him of Trisha. Six months later, out of self-loathing, Bates killed a young boy with a teenage older sister, named James Jefferson, who reminded him of himself. He then went dormant and remained that way until two years later, when he abducted a teenage girl and a young boy in Orange County (both being surrogates for Trisha and himself, respectively), took them both to Los Angeles, and killed them. The killings attracted the attention of the BAU, who had just finished another investigation.
As the BAU's investigation progressed, Bates, who was close to his endgame, abducted another teenager named Francesca Morales. Before or after that, he also abducted Trisha. After torturing Francesca by burning her, Bates attacked her house, knocking her single mother Renee unconscious and abducting her younger brother Roberto. He took all three hostages to a warehouse, doused them in lighter fluid, and set the building on fire, but not before Roberto alerted Garcia to their position using his cellphone. Bates fled but was captured by Alvez after a short fight. JJ and Alvez were able to free Roberto and Trisha, but were then forced to abandon Francesca when the flames threatened to detonate nearby gas drums. Moments after the two agents got out safely, the drums detonated, killing Francesca and traumatizing JJ in the process.
After the conclusion of the case, JJ returns home in Washington, D.C., in the middle of the night, where she catches her husband William LaMontagne, Jr. in the process of taking care of their baby son. Realizing she is still traumatized from the case, Will has JJ recount the entire story in full detail. By the time morning is upon them, Will assures JJ that it could have ended worse and that she made the best decision she could in leaving Francesca behind.
Bates targeted brunette minors, specifically boys with older sisters and teenage girls with younger brothers. These victims were surrogates for himself and his sister, respectively. He would approach his victims in broad daylight and lure them in with a ruse, such as asking them for help in finding an app on his phone. When that would not work, he would blitz-attack them and force them into his van, gagging them and binding their arms and legs together with zip-ties. He would then take them to abandoned warehouses that he selected beforehand, chain them to cots, pour lighter fluid all over them and the floors, ignite the accelerant with a lighter, and burn his victims alive. He would stay behind and watch the victims as they died before fleeing once the fire became too strong. He also forced the victims to watch each other die.
His first two victims were both runaways who were killed in the same city months apart from each other. With his third and fourth victims, he abducted them in low-risk neighborhoods (which were in different cities in California) and then took them to Los Angeles (the same city where Trisha lived) to kill them. In the case of Francesca and Roberto Morales (who were actual siblings, unlike the other victims), he abducted Francesca while she was walking in her neighborhood and presumably had her reveal her home address under torture. He then lured surveying police officers away with an arson fire before attacking the home, knocking the Morales mother unconscious and abducting Roberto.
The unsub is a white male between the ages of 25 and 35. He is also a sadistic pyromaniac, which is a rare and dangerous combination because it serves as a strong compulsive element to his psychopathy. His crimes are about watching the fires he sets as well as the mental pain and anguish that he inflicts. He is driving a truck, a van, or an RV as he needs the space to abduct and transport his victims, which also indicates that he is extremely mobile. The fact that he is not in any criminal databases suggests he has not let his habits get him in trouble and is smart enough not to get caught. Because he is well-adjusted enough to hold down a steady job, it is extremely likely that he is sublimating his desires through his chosen line of work, so he is probably working a job that requires him to be near open flames, such as a firefighter, a crematorium worker, or a cook in a kitchen. His very specific M.O. indicates that his pattern is need-based and will remain the same.
- Unspecified dates, Carson City, Nevada: Trisha Bates (his sister; attempted to kill twice, but failed both times)
- 2014, San Diego, California:
- April: Lisa Ruiz
- October: James Jefferson
- 2016, Los Angeles, California:
- October 4:
- Hannah Robertson (abducted on September 29 in Irvine)
- Max Wasserman (abducted the previous day in Anaheim)
- October 6:
- Francesca Morales (abducted, tortured by burning, and left to die in a warehouse fire; was killed in a subsequent explosion on October 6-7)
- Trisha Bates (his sister; abducted, broke both of her ankles, and left to die in a warehouse fire; was rescued on October 6-7)
- The attack at the Morales house:
- Renee Morales (Francesca's mother; assaulted and knocked unconscious)
- Roberto Morales (Francesca's brother; abducted and left to die in a warehouse fire; was rescued on October 6-7)
- October 6-7: The warehouse arson fire:
- October 4:
- Bates is based on a few unsubs on the show:
- Vincent Stiles, a family annihilator featured in Season Two. Much like Bates, Vincent was extremely psychopathic and a full-on pyromaniac who was partially motivated by both resentment (though he only channeled his resentment at others while Bates also had self-loathing) and the rejection of a woman he knew, and used arson fires as a means to kill his victims. Both also took immense pleasure in watching their victims burn alive up close, even if it meant endangering themselves in the process.
- Kaman Scott, a disfigured serial killer from Season Six. He was also motivated by the rejection of a woman, had scars from burn-related injuries, committed their crimes in the month of October (though Bates killed his first victim in April), would abduct his victims and put them in his van, take them to abandoned warehouses, and kill them by burning them alive as they watched up close.
- John David Bidwell, a vigilante from Season Ten. Both were killers whose names began with "John David", abducted young boys who were surrogates for themselves, operated in multiple cities in southern California (including San Diego and Los Angeles), victimized their sisters when they were young, and had stressors in which they were somehow rejected by women.
- Antonia Slade, a female serial killer also seen in the previous season. Both were psychopathic serial killers who suffered from self-loathing and targeted minors of both genders, who were surrogates for both themselves and someone close to them.