Just ran across the following thought you might find it interesting.
1881 "History of Iowa County, Wisconsin : containing an account of its settlement, growth, development and resources, biographical sketches" pub. by Western Historical Co. (FHL film 1,036,214 item 4; the "Lead Region" includes adjoining states)
Pg.775-6: The Murder of F.S. Clopton. In the early mining days, when the lead mines were overrun with a desperate and devil-may-care class of adventurers, life was a source of much anxiety to the more peaceable and well-behaved miners. Crime was rampant, as, owing to the cumbersome nature of the laws, criminals could easily flee the country before the intricate machinery of justice could be brought into action.
The proximity of claims and diggings were, in many instances, fraught with peril, as the turbulent classes never hesitated for a moment to forsake a barren lead, and, by force of intimidation, dispossess the claimants of more profitable land. In 1829, a case of this nature occurred, resulting in the murder of a miner and the subsequent conviction of his assassin. Two brothers, named James and Robert Duncan, were working a lead on the road running from Galena to Mineral Point, near the State line. Their labors did not prove prosperous, in strong contradistinction with the efforts of a neighbor, F.S. Clopton, whose contiguous claim afforded a reasonable return for the toil expended. He daily waxed more indignant at his own impoverishment and he began to covet the adjacent lead. This covetous spirit led to the exchange of angry words and the creation of a bitter enmity between the rival miners. James Duncan called in the aid of two fellow spirits, called Wells and Richardson, who agreed to provoke a quarrel. Their plan of action was not divulged, nor was any one apprised of the brewing storm until the morning of April 6, 1829. Then Wells and Richardson, accompanied by James Duncan and J. Scott, appeared in the vicinity where Clopton and J. Van Matre were industriously plying the pick and spade. Wells and Richardson were armed with rifles, and approaching the laborers, entered into conversation.
Van Matre inquired what was the unusual circumstance that caused them to be armed.
"To defend our property and our lives," was the lightning response, and suiting their actions they both drew a bead and fired. At the first discharge, Van Matre exclaimed "I am shot!" and on the second fire Clopton fell to the ground. Robert Larance and James Duncan carried the wounded man into his humble cabin, and placed him on his rough bed of boughs and straw. He expired in a few minutes, his last words, addressed to a cluster of sympathizing miners, being, "I forgive Wells for killing me, he was instigated to it; I blame James Duncan and McKnight for my death." With these words of fortitude, his soul took its flight. In the meantime, the murderers hastened home, and mounting two trusty horses, fled toward the river. Prior to their departure, they hastily concluded a sale of their claim to James Duncan, for $200. Getting wind of their precipitous flight, J.B. Estes followed in pursuit, but did not succeed in capturing the desperadoes.
James Duncan was arraigned before John Marsh, Justice of Peace of Crawford County, charged with being an accessory to the murder. He was indicted for the crime, and, on furnishing bonds of $2,000 to appear at the ensuing term of the District Court, at Prairie du Chien, he was admitted to bail. His subsequent career is unknown