He is the Gunsmith in Armadillo so the player will come in to contact with him when they visit the shop. He sells ammunition and guns. The player can also sell hides, skins, furs, and other provisions to him. His shop is located in the middle of town two buildings down from the doctors office.
Dewey Greenwood regularly comments on Jeb. He often remarks that "there is something odd about that Jeb Murphy".
Whilst inside or around the gun shop, the player may hear some citizens mention that Jeb recently lost his son.
Jeb often comments on Marshal Leigh Johnson and accuses him of various wrongdoings.
He is very enthusiastic towards his customers.
Sometimes when entering the store, he will not be there. He can be found out the back door smoking, urinating or fiddling around with a revolver. He will then move to the desk to serve the player.
If the player attacks Jeb with his fists and pulls a gun out before he runs away, Jeb will pull out a repeater and start firing, causing him to be shot by the law as long as the player doesn't shoot him. However, he can take a large amount of damage from non-player characters before he dies.