Spicer became a lawyer and worked as a attorney and mining engineer at Salt Lake City. He also played an active role in politics and was a unsuccessful candidate for election to the Utah Legislature in 1874. He was also unsuccessful in his attempt to defend John D. Lee when he was charged with the Mountain Meadows Massacre.
In 1878 Spicer moved to Tombstone where he worked as an attorney, mining broker and U.S. Commissioner for Deeds. Spicer lost his reputation as a honest lawyer when he used his role as Kate Holliday's attorney to get her to leave town after she provided evidence that Doc Holliday was guilty of murder and robbery.
Spicer was the judge in the court case that followed the Gunfight at the OK Corral. After a 30 day trial Spicer decided decided that the defendants (Virgil Earp, Wyatt Earp, Morgan Earp, Doc Holliday) had been justified in their actions. This judgement brought his law career to an end and after 1881 worked as a mining engineer.
The cowboy element at times very fully predominates, and the officers of the law are either unable or unwilling to control this class of outlaws, sometimes being governed by fear, at other times by a hope of reward. At Tombstone, the county seat of Cochise County, I conferred with the Sheriff upon the subject of breaking up these bands of outlaws, and I am sorry to say he gave me but little hope of being able in his department to cope with the power of the cowboys. He represented to me that the Deputy U.S. Marshal, resident of Tombstone, and the city Marshal for the same, seemed unwilling to heartily cooperate with him in capturing and bringing to justice these outlaws.
In conversation with the Deputy US Marshal, Mr. Earp, I found precisely the same spirit of complaint existing against Mr. Behan (the Sheriff) and his deputies. Many of the very best law-abiding and peace-loving citizens have no confidence in the willingness of the civil officers to pursue and bring to justice that element of outlawry so largely disturbing the sense of security, and so often committing highway robbery and smaller thefts. The opinion in Tombstone and elsewhere in that part of the Territory is quite prevalent that the civil officers are quite largely in league with the leaders of this disturbing and dangerous element.
Something must be done, and that right early, or very grave results will follow. If is an open disgrace to American liberty and the peace and security of her citizens, that such a slate of affairs should exist.
On a blustery day toward the end of October, 1881, the town of Tombstone, Arizona, witnessed the most notorious shoot-out in the history of the West. In a vacant lot at the rear of the O.K. Corral, City Marshal Virgil Earp and his brothers Wyatt and Morgan, joined by a gambler friend, Doc Holliday, exchanged gunfire with four local cowboys, the Clanton and McLaury brothers. "Three Men Hurled into Eternity in the Duration of a Moment," blared the headline over the first report of the affair in The Tombstone Epitaph. The duration, in fact, was slightly more than half a minute, although a deadly staccato of vengeful gunfire echoed for months afterward.
The clash was not unique. Possession of firearms was far more commonplace on the frontier than back East, and newspapers across the West carried accounts of gunfights of every variety - saloon brawls, outlaw raids, vigilante wars and even an occasional face-off in the style of European duels. But the shoot-out at the O.K. Corral was better documented than most, and its fame as a classic confrontation of gunfighters was well deserved, for it embodied some basic frontier animosities - lawman against outlaw, cardsharp against cowboy, citified carpetbagger against weather-beaten settler.
Yet these divisions were far from clear-cut, as the shoot-out also made plain. Though some Western gunfight participants represented the law, the line between bad men and good was, at best, blurred. The facing foes usually had more in common than they cared to admit. Most were men of bristling spirit and minimal compassion or scruple. When they had scores to settle, it hardly mattered which side of the law they were on; their law was the gun.
We live mostly in canvas houses up here and when lunatics like those who fired so promiscuously the other night are on the rampage, it ain't safe, anyhow!
When we consider the condition of affairs incidental to a frontier country, the lawlessness and disregard for human life; the existence of a law-defying element in our midst; the fear and feeling of insecurity that has existed; the supposed prevalence of bad, desperate and reckless men who have been a terror to the country, and kept away capital and enterprise, and considering the many threats that have been made against the Earps. I can attach no criminality to his unwise act.