It's been nearly 2 years since I opened this subject on this forum. Since then, I have reached out to NARA, read the various recommended books, and even contacted the University of Iowa Library, which has some source material on the 1st Iowa cavalry. I have not been able to find the complete report that begins:

Headquarters Detachment, 1st Iowa Cavaley
Warrensburg, Mo., 17 April 1862

Testimony as to cause and maner of death of Jas. A Turley; burning of house, furniture,etc., of Col. McCowan and Mrs. Brinker; Shooting of Mr. Burgess & his brother and burining of their dwelling;and killing of Piper & burning of houses of Oliphant, Doak, Thompson, and Janes

Any new ideas or leads that may have emerged in the past 2 years which could help me find this report would be greatly appreciated

Dave Burgess