Roy Sanders is a Navy Lieutenant who was fatally poisoned with thallium prior to Dead Man Walking (episode). He and Ziva crossed paths each morning when running.
A Navy Lieutenant who worked with the International Atomic Energy Agency that investigates Nuclear and Radioactive weapons, Sanders was poisoned when he smoked his own favourite cigars. His colleague, Mark Sadowski also fell ill although it's not known if Mark died.
It was eventually revealed that Holly Stegman, a colleague was responsible for poisoning the two.
Although he was treated, Roy eventually died from the effects of the poisoning.
In the next episode, Skeletons (episode), Ziva reveals that Roy died and throughout the remainder of season four, she was seen wearing his orange beanie as an attempt to keep Roy's memory alive.
He had one sister who had a husky and a child. He left all his things to her and tells Ziva that he and his sister fought as children. He also had older parents who lived far away. His mother was devastated by his illness and imminent death. He tells Ziva his father is trying to fix it which Ziva compares to her own father. He said his father was hard on him. He asks Ziva to meet his parents, and then he asks her if that is weird, but Ziva tells him that she will meet his parents.
- Like Timothy McGee, Roy Sanders is left-handed.