John D.

John D. was a member of the Railroad in 2266.

Background
In November of 2266, he was the sole survivor of a raid on the Railroad's HQ; Wyatt cites him as a major force in the group's subsequent reorganization. His recruitment methods proved to be the basis of the Railroad's "pyramid" structure of information distribution, and he is credited with the development of their dead drop system.

Records left by Pinky Thompson make no mention of his fate following the 2273 Institute ambush that killed Wyatt. However, Desdemona privately suspects that he survived and now goes under the alias Deacon.

Appearances
John D. is mentioned only in Fallout 4.