Edgar Watson is the son of Mama Watson and a member of the Watson Boys. At some point in his life, Edgar became incarcarated and was to be executed publically by hanging, but escaped jail just hours prior.
Events of Red Dead Redemption 2
Some time after Arthur interacted with and, optionally, robbed Mama Watson, Edgar and his brothers visit their mother to tell her about trying to use the money they get from their criminal exploits to move her out of the country. She will express disinterest in the plan.
If Arthur attempts to enter the house, the brothers will attack him, and he has the option of killing them all, subduing them, or simply running away.
- Mama Watson's scrapbook