Galaran scientist assigned to the Galaran memory project alongside Dr. Reya Varrick (his ex-wife) and Dr. Amuro. Like his colleagues Dr. Marell was not keen on the military stepping in and taking control of his work on the memory technology.
Though separated from his wife for two years, Marell -- who had hoped to some day reconcile with Reya -- could not stand himself when he saw her leave a party with Colonel Cameron Mitchell. He followed the two back to her home where he rendered Mitchell unconscious with an electrical discharge. He grabbed a small statue and struck his wife, killing her. He then took Mitchell to the memory facility, transplanted the memory of Varrick's death from his own mind into Mitchell's, and replaced it in his own with a grafted memory from a few nights before.
Because he had forgotten he committed the crime (to dispel the guilt), Marell was anxious to clear Mitchell's name of any wrongdoing. However, having two identical memories in his mind was what eventually exposed his crime.
When the evidence came forward the Galaran Emissary, instead of sentencing him to a punishment, wiped the last few days of memories from his mind. Marell now believed Varrick had died in an accident. To SG-1's dismay, the killer was immediately put back to work on the project that remains so important to his government.
Collateral Damage - Enraged by jealousy, Dr. Marell follows Colonel Mitchell and Dr. Varrick back to her home, where he kills her and later conceals the atrocity even from himself.