Mayfield was a fugitive from justice from Carson City, Nevada, where in the Winter of 1861–62 he renewed an acquaintance with Henry Plummer, whom he had known before that time in California. The Governor of California had issued a requisition for the surrender of Plummer, and a warrant for his arrest was in the hands of John Blackburn, the sheriff at Carson City. Though efficient as an officer, Blackburn, while in liquor, was overbearing and boastful of his prowess. His reputation was bad among the leading citizens of the town. Foiled in his search for Plummer, who, he believed, was in the Territory, and knowing of Mayfield’s intimacy with him, he accused the latter with concealing him. Mayfield denied the charge, and to avoid a quarrel with Blackburn, who was intoxicated, immediately left the saloon where the interview occurred, but as a measure of precaution armed himself with a bowie-knife. Blackburn, rendered desperate by liquor, soon followed in pursuit of him, and at a later hour of the same day found him in another saloon. As he entered the front, Mayfield tried to leave by the rear door. Failing in this, he drew his knife, and concealed it in his sleeve. Approaching Mayfield in a bullying manner Blackburn said to him, “I will arrest Plummer, and no one can prevent it. I can arrest anybody. I can arrest you if I wish to.” “You can arrest me,” replied Mayfield, “if you have a warrant for my arrest, but you can’t without.” “I tell you,” rejoined Blackburn tauntingly, “that I _can_ arrest you, or any one else,” and added with an oath, “I will arrest you anyhow,” accompanying this threat with a grasp for his pistol. Mayfield, with flash-like quickness, slipped his knife from its place of concealment, and gave him an anticipatory stab in the breast. Blackburn then tried to close with him, and being much the stronger man would have killed him had not Mayfield jumped aside and plied his knife vigorously until Blackburn fell. He died almost instantly. Mayfield surrendered himself for trial, was convicted of murder, and sentenced to be hanged.