Pindall did say that the information about Parsons' death was contained in the letter of Capt. [Silas?] and Col. D.A. Williams. However, I don't know if this letter is on file somewhere. I don't see it, or any memoirs by D.A. Williams, listed in Jim McGhee's book, Missouri Confederates: A Guide to Sources for Confederate Soldiers and Units 1861-1865, but Mr. McGhee is always finding new information and is definitely the one who might know what and where.