This is one of the few traditions in the atlas that can be studied while it is being formed, and the documentation reflects that.
There is no scripture and no founding text. What exists is the shrines themselves, the objects sold and used at them, the prayer cards, the visible growth in the number of altars, and the testimony of devotees. Much of the primary evidence is ephemeral and commercial, which makes it easy to collect and easy to misread.
Ethnography from the late twentieth century onward is the main scholarly resource, and it has had to work against two distorting pressures. The Catholic Church has condemned the cult of Santa Muerte in explicit terms, which shapes what practitioners will say and to whom. And press coverage has tied these devotions tightly to organised crime, which is part of the picture and is very far from all of it: the majority of devotees are ordinary people in precarious circumstances, and researchers have had to say so repeatedly against a stronger narrative.
Historical work on the individual figures is possible in a way it is not for ancient traditions, because the people involved were real, recent and documented. Court records, newspapers and civil registers exist for the executions that founded these cults, and comparing what those documents say with what devotees say is itself one of the more revealing things this material offers.