Thank you for your kind reply. I have begun to follow the trail through archives and old records in Camden, Alabama. Since Lt. Holt was from Tennessee, my only hope with Alabama archives is that his death will surface in a local newspaper due to the uniqueness of the incident (if one could say execution, "killings", or murder were unique during this period), or, maybe, there will be an entry in a county or city record.
I am sure that my great-grandfather, John Holt (Lt. Joshua Holt's son), knew exactly what happened, but he died before my mother was born and no family record exists. I have looked through many histories of Forrest and his Escort and have not found any reference to Lt. Holt's death other than "killed after surrendering." The veterans of Forrest's Escort had to have known stories of Joshua Holt's death and I am sure they shared them with his son, John, since John was made an honorary member of their veterans' association.
The only family story from this era is of an incident where Joshua Holt, while carrying a unit flag, had a hard-to-control horse run away with him taking him into the middle of the enemy. This may have happened when he was badly wounded during action around Okolona, Mississippi the day Forrest's brother was killed.
Thank you, again, for your interest.