Founding Fathers were addressing the issue of colonists being transported to England for various trials. Trials that had been held in the colonies often found colonial citizens not guilty and British soldiers guilty. By transporting colonists to Britain for trial they could possibly get the better outcome that they wanted (guilty verdict). The courts is England were often more sympathetic to the Crown and government, just as the courts in the colonies were sympathetic to colonists and colonial causes.
They attempted to fix this by adding the various due process amendments, namely the right to a speedy trial (6).