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Leader of the group that stormed Carthage Jail and murdered Joseph and Hyrum Smith. Williams was listed as one of the "leading members" of the New Harmony Church:
Documentary Proof of Names of New Harmony Church Members During the 35 years this church existed, there were over 50 baptisms, and over 45 members received by letter. A complete list of names of members cannot be compiled without finding the New Harmony church records, but some of the names of the members of this church appear in the Minutes of Salem Association. The minutes of Salem Association of Regular Baptists are in existence from their inception, in October 1835, and New Harmony Church was one of the original member churches. The Salem Association minutes, which were published annually, and recorded in manuscript form in a record book, provide documentary proof of the names of about 35 of the leading members of New Harmony Church. Among them are some of the earliest and most prominent settlers in this part of the county. The names of male members which we can document include: John Walker, George Walker, Eli Walker, Robeson Gillham, G. J. Baker, J. B. Couch, Zachariah Barnett, Curtis Caldwell, Pleasant P. Glenn, Isaiah Guymon, David Layman, Hampton Loftis, John Martin, William McCrady, Reubin Shepherd, A. P. Tanneyhill, Isaac Vinson, Hiram Woodworth, and Colonel Levi Williams. 
George A. Smith called Williams a "Baptist preacher,"
But I told them that the Rev. I. McCoy, a Baptist minister, with his gun on his shoulder, at the head of forty men, drove women and children out of their houses and robbed them in Jackson county, Missouri, in 1833; that Levi Williams, a Baptist preacher, led the party of men who murdered Joseph Smith; and that the Rev. Thomas Brockman, of the Reformed Baptists, at the head of 1800 men, drove forth to perish 500 or 600 Saints, men, women, and children, poor and helpless, who were left in Nauvoo, Ills., having previously cannonaded the town for three days.
Fawn Brodie notes that Williams led the group that stormed Carthage Jail,
For an instant he hung to the sill swinging, while Levi Williams, the colonel commanding the Warsaw militia, shouted: "Shoot him! *** **** him! Shoot the damned rascal!" But no one shot.