Marell is a male Galaran.
In 2006, he murdered Reya and implanted the memory in Lt. Colonel Cameron Mitchell and deleted it from his own memory using the Galaran memory device. By erasing his own memory of the murder and framing Mitchell for it, Marell could absolve himself of the guilt. However, he didn't count on Mitchell's determination to investigate. Incidentally, Marell and his colleague, Dr. Amuro, assisted Mitchell in uncovering his crime. When Mitchell recalled the implanted memory, he saw his own face in the mirror but the face was blurred, because his brain could not resolve the conflict between the implanted false memory (of Marell's reflection in the mirror) and his own expectation of what "should" have happened (of the reflection being Mitchell's own face). Marell and Amuro adjusted the image to remove this conflict, after which Mitchell could see that the murderer was actually Marell. Because Marell had removed the memory from his own mind, he was surprised to learn that he was actually the true murderer. Examination of Marell's memories indicated that he did tamper with his own memories to erase the memory of the murder, replacing it with an exact copy of a memory from several days before. It was apparently impossible to re-implant the memory of the murder into Marell's mind again, and so the conclusion of the investigation (that Marell was the actual murderer) was again erased from Marell's mind. Marell continued as lead researcher of the memory project, and continued to believe that Reya had died in an accident. The administrator of the project pointed out that Marell had no memory of committing the murder, so he could hardly be punished. He also claimed that Reya would have understood the necessity of this subterfuge. (SG1: "Collateral Damage")