Harold Thornton

Harold Thornton is a minor character featured in Red Dead Redemption.

Thornton is the subject of the Stranger mission The Wronged Woman.

Background
Harold cheated on his wife, Elizabeth, with his children's nanny, Clara. He later kicked her out with no money or shelter. After meeting, Clara asks Marston to get some money for her, and when confronted with the accusations, Harold denied them and challenged Marston to a duel, resulting in Harold's death.

When told of Harold's death, Clara cried and said she could still make it to the funeral. A few days later, Marston met Elizabeth, Harold's widow, in the cemetery. Elizabeth mentioned that Clara was laughing at the funeral and then left Marston to consider his role in the events that transpired. John never mentioned to Elizabeth that he was the one who gunned Harold down.

While some speculate that Clara and Harold never had an affair, there's no way to know. Harold denied it, but he died before the truth is ever revealed. It would seem more likely that Clara was seeking revenge for being used and then discarded by Harold when her pregnancy was obvious and Marston was duped into being the instrument of her vengeance against Harold.

Interactions
In the stranger mission The Wronged Woman you meet him in a duel when he refuses to give you money for the woman he kicked out. You kill him and then loot his corpse for money. You can later find him in Blackwater cemetery where you will continue the stranger mission by speaking with his widow.

Trivia

 * Considering his thick accent (and his last name) it's possible he is of Scottish descent.
 * Thornton's gravestone read's "The Truth Shall Make You Free", which could be a reference to the possibility that Clara was not impregnated by Harold and she was lying to Marston, which is implied by Elizabeth