Captain Rumford was a character in Diablo III. He was placed in charge of the militia defending New Tristram from the Risen following Captain Daltyn's death. He was a farmer prior to the appearance of the Risen.
At the start of quest Trailing the Coven in Act I, he will no longer be found in the center of town. Upon leaving New Tristram and heading towards the Old Ruins, he can be found lying dead at the bridge.
His ghost/soul has a chance to appear in Act IV, but upon interaction, he will accuse the Nephalem of letting greed drive their actions, and failing to save him. After that, he turns into the monster Aspect of Sin.