From TARDIS Index File, the free Doctor Who reference.

Asa Bamford and his brother George were southern outlaws in the 1860s. They accosted the Doctor and Charlie Fisher, who were trying to get the Doctor's TARDIS back from the Union Army. After attacking the wagon train transporting the ship, the brothers forced the Doctor at gunpoint to open it, thinking that it contained money. After using some Venusian karate on them, the Doctor offered to transport them to somewhere else in the world to start a new life, as he had to Charlie. The Bamfords, frightened, instead asked to be let out, where they were immediately captured by Union soldiers. (TVA: Backtime)