The corpse is a witch. She lived in an era when humans were afraid of witches, so people tried to kill witches in various ways, but witches were too powerful, and they could not completely kill witches in various ways (using narcotic flowers, using all kinds of forbidden drugs). In the end, they could only break their hands and feet and bury them in the soil, but they could not prevent people who did not know this kind of power from gradually resurrecting the witch, and the witch's brain was still alive and even visible. , using various illusions can trick other people to repair themselves until resurrection, and the condition of the witch's resurrection is probably to make others believe that she is a witch and willing to sacrifice herself
"any man or woman who ...of the dead shall be put to death for they are a witch"
Anyone who contacts the spirit of a dead person (probably a psychic) should die because they are witches
This also explains why the corpses are controlled by her, which can also be said to be an illusion.
As long as you know these points, the feeling will be opened. As for the other doubts in the film, it is not the point.
View more about The Autopsy of Jane Doe reviews