Charles attended high school during the early 1960s, a time when African-Americans were specific targets of racial discrimination; he also lived in Virginia, where the discrimination was especially strong. In 1961, when he was a senior, he was attacked by six members of a local chapter of the Ku Klux Klan, who assaulted him and took him into the woods. They were under the assumption that he raped a fellow schoolmate named Audrey Collins, who was the half-sister of Karl Beck, one of Charles's assailants. In reality, she was past her curfew because she was having sex with her boyfriend. In the woods, the KKK members hung Charles by his wrists and castrated him. For the rest of his life, Charles grew up taking testosterone pills and being resentful of the men who attacked him. During his adult life, he met and married a woman named Tina, but was unable to conceive a child due to his castration. As a result, Tina resorted to (apparently) a sperm bank and had a son, whom they named Lyle.
In 1978, after receiving a letter from Audrey, who confessed to her lie, Charles snapped and murdered two of the men who attacked him as a teenager, beating them to death and mutilating their genitalia. He then buried their bodies in his backyard. He also planned to attack the other men, but many of them, by that point, died due to natural causes. However, in 2003, when Lyle began dating a schoolmate named Mary Ann Beck, who turned out to be the daughter of one of the men who died before he could get to him, Charles snapped again at the fact (plus the fact that his son was dating a Caucasian woman) and murdered her in the same manner as his 1978 victims. The latest murder apparently inspired him to target Rachel Mills, the daughter of another of his assailants, and kill her as well. As with the 1978 victims, he buried both Mary Ann and Rachel in his backyard. Then, Charles became inactive, spending the rest of his years until 2013 working as the founder and head of his construction company, J&J Contractors, alongside Lyle.
In the episode, Charles and Lyle return home from their work to find the BAU and police searching the family house and digging up the backyard, having found two of Charles's victims that were exposed after a drainage pipe exploded and flooded the backyards of several houses in the neighborhood. Charles asks Tina, who is protesting against the search, what is wrong, and she tells him about the skeletons found in the backyard and that the entire family is being put under suspicion. He then acts calm as Lyle flees from the scene after being spotted by Hotch. After Lyle is captured, the entire family is taken to a local police station for interrogation. Throughout the first half of the episode, Lyle is suspected of being the killer, since one of the skeletons has been identified as belonging to Mary Ann, whom he would have logical reason for killing. However, when Lyle is let off the hook after the body of one of his 1978 victims, identified as James Moses, is found, the focus of the investigation then shifts to Charles after his stash of testosterone pills is found. When Rossi interrogates him, he reveals his strict nature towards Lyle, as well as his disappointment in Lyle's gender, citing several controversial cases in recent history (in which African-American teenage boys were killed out of alleged racism) as the reason for such disappointment. When Lyle is exonerated, these statements cause the BAU, who shift their focus on Charles, to believe that racism might be a key factor to the killings.
Later, in an attempt to extract a confession out of Charles, Rossi buys him lunch. Then, as Charles eats, he tells him about his experiences as a teenager, in which he was bullied and racially discriminated since he was Italian. Taking advantage of this, Charles taunts him with racial slurs and asks him to tell him about an experience in which he bullied someone of another race. Rossi tells him about one time in high school where he was pressured by several white members of the baseball team he was also a part of to shove a fellow African-American player into a locker, urinate on him, and then leave him locked inside for the night, which Rossi did. Rossi then tells him that he changed, citing that one of his ex-wives and a friend of his were African-American, but Charles taunts him about the incident before grabbing his soft drink and aggressively tossing it at Rossi, spraying him and the one-sided window with liquid. Morgan then tries interrogating him, but he repeatedly requests to talk to Rossi. Later on, when Garcia finds out about Charles's castration attack and the motivations behind it, Rossi confronts Charles about it and then threatens to tell Lyle that he isn't his son. Intimidated by this, Charles decides to write out a confession in exchange for silence about Lyle's true heritage. At the end of the episode, Rossi goes to a locker room to get his belongings, and as he does so, he hears the baseball players taunting him to urinate on the African-American player, revealing that the incident actually happened.
During the 1978 murders, Charles targeted the men who were involved with his abduction and castration, while during the 2003 murders, he targeted the daughters of the men he was unable to seek revenge on due to their deaths through other causes. He would beat all of his victims to death with his bare fists, mutilate the victims' genitalia post-mortem (according to a confession from him), and bury their bodies in his backyard.
No official profile of Charles was made. However, the BAU judged him to be a sociopath due to his calm and controlled demeanor, and also his manipulative, taunting attitude towards Rossi.
Note: All of the dates denote when the victims disappeared
- July 1: James Moses
- September 9: An unidentified man
- July 8: Mary Ann Beck (the daughter of one of his assailants and Lyle's girlfriend)
- July 18: Rachel Mills (the daughter of another one of his assailants)
- Charles is partially similar to Season Seven criminal Michael Janeczco. Both were serial killers who had stepsons, were motivated to kill by emasculation (which played a factor in them having stepsons instead of biological sons), killed at least one victim out of revenge, and had an M.O. that involved doing something to their victims' genitalia (Micheal removed the genitals of his victims post-mortem, while Charles mutilated his victims' genitals).
- Charles is one of few serial killers on the show to successfully kill all of the victims he targeted. The others are Steven Fitzgerald, Megan Kane, Vincent Rowlings, Paul Westin, and Larry Feretich. This is a very rare occurrence, as the serial killers depicted on the show typically have at least one survivor.
- Charles is the third unsub in the series to have a 25-year cooling-off period, the second-longest cooling-off period as featured in the show's history. The first two are James Stanworth and Tory Chapman.