In 1992, Nemman signed the autopsy reports for the autopsies of three teenagers, including Ray Soames. However, Dr. Nemman intentionally missed out the fact that the teenagers each had two small bumps on their lower back. While Nemman was on holiday with his family, a teenager named Karen Swenson died in similar circumstances as the three teenagers that Nemman had autopsied. Another medical examiner was assigned to perform the girl's autopsy and noted the two small bumps that she had. When the case was reported to the FBI and added to the X-files, Special Agents Mulder and Scully discovered that the autopsy reports did not match.
They traveled to Bellefleur, Oregon, where they met Dr. Nemman just as they were about to exhume Ray Soames' coffin from a cemetery to check whether he had the small bumps on his back. Nemman arrived at the scene in a Jeep Cherokee. At first, he struggled to stop his daughter from interfering in the situation. After he had managed to return his daughter to the car, Nemman protested against the FBI's use of the cemetery.
When he revealed that he and his family had just come back from their holiday, Mulder realised that was the reason why he hadn't conducted the autopsy on Karen Swenson. The agents told Nemman of their discovery, but the doctor claimed that the agents were accusing him of missing something in the autopsies he had conducted. Nemman demanded some proof that he had missed out information and eventually left at his daughter's insistence.
Later, Nemman's daughter, Theresa, sought the protection of the FBI agents as she was scared that she might die like the other teenagers - her classmates. Theresa revealed that she sometimes found herself in the woods with no recollection of how she got there. She also admitted that her father knew this would occasionally happen to her, but had told her not to reveal anything about her experiences to anyone else. According to Theresa Nemman, her father believed that he could protect her but she disagreed.
Dr. Nemman entered the diner with Detective Miles and tried to convince his daughter to return home with him. Mulder suggested that Theresa might not want to leave, but the medical examiner shouted that he didn't care about Mulder's suggestion. Dr. Nemman added that his daughter was sick and told Theresa that he would take her to a safe place.
After Miles, Nemman and his daughter left, Scully reminded Mulder that the medical examiner had lied on the autopsy reports. She suspected Nemman of being responsible for the destruction of an autopsy lab that she and Mulder had used, and for a fire that burnt down the motel rooms where the agents were staying. (TXF: "Pilot")
- In the first draft of the script, the character was named Dr. Neuman. In the final episode, Cliff DeYoung played Doctor Jay Nemman.