He and two other gang members arrive at Pronghorn Ranch, where they are seen harassing Abe. He tells Abe to convince his boss to sell the land, threatening to start killing people on the ranch otherwise. He then fires his revolver near to Abe's feet to scare him, saying that he’ll be the first to be killed. John Marston intervenes, and the gang leader insults him. John calls his gang “vermin”, angering the gang leader. He then punches at John, who dodges, starting a fight. John defeats the gang leader and continues beating him up, until Abigail intervenes and tells John to stop. The gang leader threatens to return to the ranch and leaves with the two gang members.
The Laramie Gang decides to attack the ranch in retaliation for John attacking their leader and Geddes refusing to give up the land. They kill a ranch worker, set fire to some structures and steal the cattle from the ranch. David Geddes asks John, Abe, and Tom to help him get back his cattle. The group heads to Hanging Dog Ranch, where the Laramie gang are located. John, Abe, and Tom kill the Laramie gang members. The gang leader soon hides in a barn and is angry that John and the others killed his gang members. When John enters the barn the gang leader jumps down to attack John, but John breaks free and subdues the gang leader. The gang leader then grabs a Sawed-off Shotgun to shoot at John, but John kicks the gun out of his hand. He then taunts John for a final time, before John shoots him with it.
He is shown to be very cruel, and has little regard for the lives of others as long as it lines his pockets. He also appears to be attracted to Abigail, as his last words involve wanting to sleep with her. However, considering his hate for John,it's likely he wasn't being sincere.
It was widely speculated that the Laramie gang leader was voiced by Steven Ogg due to him sounding similar to Grand Theft Auto V's Trevor Philips, although he confirmed that he did not voice the character.
Tell your friend, Mr. Geddes, he's gonna sell this place...