The doctor is indeed mysterious. A check with the Dallas County Medical Society showed that Dr. Mendoza first registered in April 1976, less than two months before he began treating DeMohrenschildt and at the same time the House Select Committee on Assassinations was beginning to be funded.
Mendoza left Dallas in December, just a few months after DeMohrenschildt refused to continue treatments, at the insistence of his wife. Mendoza left the society a forwarding address that proved to be nonexistent. He also left behind a confused and unbalanced George DeMohrenschildt.