"I didn't kill her, I just... I really wanted to."
Nathan was born sometime in 1991. His father died when he was nine years old, leaving him to be raised by his mother, a doctor and teacher at GW Medical School, who didn't remarry. For reasons unknown, he developed sexual sadistic impulses over time. Among other things, he mentioned that he felt glad while killing a bird and also becoming sexually excited when he saw a pair of nude female cadavers used by his mother for teaching; it was not because they were nude, however, but because they were dead. When he grew older, he started researching about sexual sadism in an attempt to understand his urges.
Sex, Birth, DeathEdit
At the beginning of Sex, Birth, Death, he is a sophomore at the Morton School. A few weeks after attending a seminar on anger excitation by Reid, he comes across the first victim of Ronald Weems, a serial killer targeting prostitutes. Feeling excited by the sight of her corpse, he waits for Reid at the subway station he usually takes to the FBI. After asking a few increasingly disturbing questions, Nathan leaves. Reid draws a picture of him out of his memory and uses it, combined with his memories of what Nathan said about himself and was dressed, to find his address. When the BAU take him in for questioning, he is writing a short story featuring graphic descriptions of a prostitute being stabbed to death, which he claims was the text for a graphic novel about Jack the Ripper. After performing a psychological evaluation of Nathan, Gideon recommends to Nathan's mother that he be placed in medical care. She agrees to have him see someone on a daily basis, but refuses to have him locked away.
Later that day, Nathan disappears. When his mother searches through his room, she finds a pornographic magazine with pictures of grotesque mutilations pasted onto the fold-out pictures. The same night, Weems claims another victim. Nathan is found at a church where he has reached a conclusion: the only way for him to prevent people from getting hurt in the future is to kill himself. Nathan is held as a suspect for Weems' murders until he is identified and captured. By then, his mother has decided to have him institutionalized the next day. Only having one night of freedom left, Nathan solicits a prostitute with the intention to kill her. Alone with her, Nathan starts to resist to his urges, produces a knife, places one of Reid's business cards on a desk, and slashes his wrists. The prostitute calls Reid, who arrives and manages to slow down Nathan's blood loss enough for the paramedics to save him. Reid later contemplates the consequences of Nathan's survival, which might endanger the lives of people in the future and asked Gideon, "What if next time he kills somebody?" Gideon replied, "Then you catch him."
When Frank Breitkopf began hunting and killing people Gideon and the BAU had saved in the past, Nathan was listed as a possible target.