|“||You think just because I'm a security guard, I don't understand sarcasm?||”|
Born on February 22, 1969, Nathan lived in Flagstaff, Arizona and was married to a woman named Cheryl, having a daughter named Sam with her. He applied to the local Police Academy on February 10, 2003, but was denied entry four months later after failing the psychological exam, with the results stating that he had a borderline personality with antisocial and sociopathic tendencies. Five months after being rejected, Nathan got a job as a security officer at a local college campus and, three years later, lost Cheryl and Sam when, after assaulting the former, she divorced him and gained full custody of Sam, with Nathan receiving no visitation rights. Depressed over losing Sam and being rejected by Cheryl, Nathan went into a downward spiral, becoming an alcoholic and growing addicted to pornography. On September 14, 2007, a mere two days after his family fell apart, Nathan killed a college student named Brenda Gladwin, who reminded him of Cheryl.
Dubbed "The Campus Killer" by the media, Nathan, a day after claiming his second victim Sharon Stanworth, murders another girl named Amy Deckerman, this one while she was waiting for the campus security shuttle. As the BAU, along with local authorities, investigate this new killing and the others, Nathan sulks in his apartment before going out in search of another victim. Finding a student on her way to her car, Nathan offers her a lift and, while he drives, attempts to make small talk. The largely one-sided conversation grows more and more disturbing, with Nathan yelling at the girl to swear that she would never abandon anyone like his ex-wife did. Nathan is then pulled over and arrested by the police and BAU, his concealed knife taken, and his intended victim rescued. At the police station, Nathan is questioned by Gideon, who tries to coerce a confession from him, due to none of the evidence they have against him being solid enough for a conviction. Refusing to admit to the murders, Nathan is held overnight and reluctantly released the next day when another murder with an M.O. similar to his is committed with a note being sent to the police by someone claiming to be the real killer.
With the campus being temporarily shut down due to all the deaths, Nathan, finding himself alienated by everyone, cleans out his locker. On his way home, Nathan is approached by a student named Anna Begley and is lured away to a secluded courtyard by her. Believing Anna wants to have sex, Nathan grows nervous after seeing a security camera trained on them and suggests they go to his apartment before Anna reveals what she truly wants from him. She committed the murder that got him released; her reason for doing so being that she wants Nathan to kill her. When Anna takes out a knife and begs him to end her life, Nathan refuses, believing it to be a setup. Walking away, Nathan is grabbed by Anna and, in response, he calls her a bitch and states that she is not going to trick him into saying or doing anything incriminating. Directly after saying this, Nathan is stabbed in the stomach by Anna. Morgan, who had been trailing him with Prentiss, tries to save Nathan, but despite his best efforts Nathan still bleeds to death. The deaths of Nathan and Anna resulted in Hotch getting suspended and Gideon resigning from the BAU.
The unsub is a white male with access, since he has managed to move in a small local community with high police presence without raising suspicion, meaning there is a chance that it is someone who has been seen by police. It is very likely that something has set him off that caused him to go off on a spree. Since the victims were all killed in non-secluded areas and lacked defensive wounds, the unsub might be living or working on-campus. He may be a student, professor, or part of a support staff. All of the victims were brunettes who were stabbed, even after death, which signifies that the unsub may have been rejected in some way by someone physically similar, such as a mother or girlfriend. He may feel emasculated and this rejection is the stressor that sent him over the edge. People will notice his devolution: he will have most likely have found religion, been drinking, or been harming himself. He displays a great amount of anger toward his victims even after killing them; he stabs his victims repeatedly post-mortem, but seconds later, he feels remorse. It is possible that his victims are in a position to trust him because he is a part of campus life.
While questioning him, Gideon noticed that Nathan chewed his fingernails, which told him that it was possibly his way of punishing himself, and goes on to say that the reason he folded his victims' arms over their chests was because he felt guilty about murdering them, as he was supposed to be their protector.
While Nathan was officially a spree killer, he shared certain characteristics of a serial killer; he targeted a specific type of victim, had a specific M.O., and kept trophies from his crimes, the last characteristic being atypical of spree killers.
Nathan targeted brunette, Caucasian, female college students who resembled his ex-wife, Cheryl. He would approach them at night when they were alone, and incapacitate them with a taser. He then killed them by stabbing them once, directly in the heart, with a knife.
His first signature was stabbing them repeatedly in the heart with a knife post-mortem. His second signature was posing them by folding their arms over their chest afterwards. The folding of the arms signified his remorse over the fact that the victims also reminded him of his daughter. Before killing his victims, Nathan made each victim swear that she would not do the same thing Cheryl did to him: have a child with somebody and take it away from them. After the murders, Nathan kept newspaper clippings talking about his crimes as trophies.
Nathan has elements in common with both Eric Rudolph, a.k.a. "The Olympic Park Bomber", and Richard Jewell, a man who helped to minimize the damage caused by the Centennial Olympic Park bombing committed by Rudolph; the latter comparison was even made in the episode by Morgan. Though his motives, M.O., and pathology highly differed from Rudolph, Nathan, like Rudolph, was the subject of a large investigation by the FBI, who committed several murders and was even given a nickname by the media as a result. Like Jewell, Nathan was a security guard who became the main suspect in the same investigation, which subsequently ruined his reputation, and he would later be exonerated without being formally charged. In the meantime, the investigation overlooked another crime, which is similar to how Rudolph was able to commit two other bombings while the public was still focused on Jewell. Both Nathan and Jewell were also still tailed by the FBI even though they were never charged with a crime. However, unlike Jewell, Nathan was responsible for the crimes he was accused of committing, while the crime committed during his detainment was carried out by an unrelated copycat.
Nathan also seems to have been based on prolific serial killer and rapist Ted Bundy. Both targeted women who resembled the women who rejected them, shared the same victimology (brunette, Caucasian, female college students), kept trophies (Nathan kept newspaper articles that mentioned his murders; Bundy kept his victims' skulls), and were given the same alias by the media. Nathan also used his job as a college security guard to get close to his victims, while Bundy dressed up as a police officer so that he could get his victims to lower their guard when he approached them.
In addition, Nathan seems to have been inspired by Kenneth Bianchi, one of the "Hillside Stranglers". Both were psychopathic killers who targeted women, applied for a job in law enforcement but were rejected, had wives who divorced them, worked as a security guard, were given names by the media for their crimes, and had female copycats (though in Nathan's case, the copycat committed her crimes on her own accord and not under his instructions, as was the case for Bianchi). His M.O. of offering rides to college students in the same campus and his nickname are similar to those of Edmund Kemper, a.k.a. "The Co-Ed Killer".
- Unspecified date: Cheryl Tubbs (his ex-wife; assaulted; punched in the eye)
- September 14: Brenda Gladwin
- September 16: Sharon Stanworth
- September 17: Amy Deckerman
- September 18: Helen (attempted)
- According to the Cadet Records Log of the Coconino Law Enforcement Academy, Nathan's Social Security number is 987-07-1377.