I suppose I was not entirely clear in my writing, but the idea is that the followers of Santa Muerte completely sever themselves from the Catholic Church. I will admit that other than some reading on Infogalactic, I do not know much about the nuts and bolts of their beliefs, but I thought if any religious group in the world would employ necromancy, it would be them.
The extent of my research is the information found at the Infogalactic link below: