At some point prior to 1899, Billy joined Colm O'Driscoll's gang.
Events of Red Dead Redemption 2
Three days before the mission "Outlaws from the West" takes place, Billy, Tom and a few other O'Driscolls raided Sadie and Jake Adler's ranch in the far north of Grizzlies West. While Tom left sometime after the raid, Billy and some of his companions stayed at the ranch to enjoy themselves.
When Dutch, Arthur and Micah arrive at the ranch, O'Driscoll's Boys are seemingly having a good time inside the house, with Billy even playing music. After Dutch gets their attention, an O'Driscoll tells Billy to stop playing music and leave the house through the front door, while Billy can later be seen using a side exit during their conversation with Dutch. As soon as all the O'Driscolls have left the house, a shootout ensues in which Billy is killed by either Dutch, Arthur or Micah.
- Red Dead Redemption 2
- When observing the inside of the house by using a mod to go out of bounds, Billy can be seen standing at the side door seemingly playing an invisible guitar one-handed, despite the music sounding like it's being played on a violin-like instrument.