[Pelham]

It appears that a Yankee officer at the battle disagreed with the claim that there was a massacre:

“The report of Lieutenant Daniel Van Horn, Sixth U. S. Colored Heavy Artillery confirmed this in which he reported: “There never was a surrender of the fort, both officers and men declaring they never would surrender or ask for quarter.”

http://37thtexas.org/html/grandfab.html

[Mr. Lucky]

The principal "forensic" evidence for the alleged massacre was that many of the black KIA had powder burns visible on their wounds. Having won the war, and thereby getting to write the history, the Union concluded that the black soldiers with powder burns had been murdered.

By the convention of trained military officers, close quarter combat was conducted with sabers; soldiers killed in combat would have suffered saber cuts while soldiers who were executed would have revealed powder burns.

The problem is: General Forrest ignored convention; his troops at Fort Pillow were armed with Navy Colts, not sabers. Anyone Union soldier killed in close combat at Fort Pillow would have had powder burns.