Mutilating is what pagan cultures do,whether one can believe the recorded memories so long after the event. His brother Tom was so mutilated it took a tattoo to identify him. Tom was a real hero, awarded two Medals of Honor in the Civil War,and found right next to Lt.Col.Custer.
Forensics as a field, this is my interest. Not the COD—which was evident—multiple gunshot wounds to the chest, and a non-exiting left temple wound (from a distance) he did not shoot himself, though many did.
The psycho-forensics are interesting as well, excellent resource— US Army : https://ssi.army.libguides.com/littlebighorn
From a while back— a forensic archaeologic look at the battle, with controversy as well, but the mapping of shell casings is fascinating as is the scanning x-ray and metallurgy: https://www.youtube.com/watch?v=z4OjHlvqIcY
Nonetheless, he wasn’t scalped.