Brant Gardner notes that while the idea of scalping typically invokes visions of the Indian wars of the American northeast, the idea of scalping was not foreign to the Mesoamerican scene. While there is not as much information available on the practice, there is nevertheless evidence that scalping was a part of Maya warfare. [Brant Gardner, Book of Mormon Commentary, [http://www.highfiber.com/~nahualli/] LDStopics/Alma/Alma44.htm, p. 4]
“He Took off His Scalp”
According to T.J. O'Brien, in an unexpected reversal, some bizarre Indian practices abhorred by the Spaniards and usually thought of as unique to natives of this land are also found in ancient Israel: scalping, eating of sacrificial victims, "Holy Wars," and displaying the heads of sacrificial enemies. Other practices, surprisingly found in both Biblical and Indian cultures, were bows and arrows (1 Chronicles 12:2) and smoke signals. Both also employed the more pleasant social customs of washing the feet of strangers and anointing them with oil. [T.J. O'Brien, Fair Gods and Feathered Serpents, p. 198]
“He Took off His Scalp - Scalping”
According to Daniel Ludlow, the question might be raised as to whether or not the "scalping" of the Lamanite leader, Zerahemnah (Alma 44:12-14--"he took off his scalp") might have led to the scalping tradition of the American Indian. However, recent evidence would seem to indicate the American Indian did not have a scalping tradition until after the coming of the white man . . . that is, until the 17th century A.D. Apparently it was the white man who started the scalping custom, when some of the early colonists offered money for the scalps or hair of dead Indians. In order to get even with the evil white men who killed Indians just for their scalps (in much the same way as they would kill a buffalo for its hide), the Indians started to kill and scalp the whites in return. [Daniel H. Ludlow, A Companion to Your Study of the Book of Mormon, p. 232]