Complex sentence: He became a member of the "Committee of Vigilance" in Tombstone, an organization of local citizens in support of law and order, which brought him into regular contact with lawmen Fred White, Wyatt Earp, Virgil Earp, Johnny Behan, and Morgan Earp.
Split into simpler sentences: He became a member of the "Committee of Vigilance" in Tombstone, an organization of local citizens who supported law and order. His role brought him into regular contact with lawmen Fred White, Wyatt Earp, Virgil Earp, Johnny Behan, and Morgan Earp.