There are over 170,000 tribal members. As with any culture there are members that do not follow the laws of their people. Some of these people are witches. Through ancient native spiritual abilities and powers they have the ability to imitate the animal whose skin they are wearing. The Skinwalker uses witchcraft.
Witchcraft is evil magic a person uses to do harm to another person.
According the Navajo Medicine Woman's website, one of the ways a Skinwalker places its evil hexes is by using a witchcraft bundle. Witchcraft bundles are used to place hexes and curses on a person. They are usually placed where the person lives or is around a lot. One way to fight against the evil magic is by a medicine bundle. Medicine bundles are used to prevent and protect the person from hexes and curses.