"Science, my boy, is madd up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth." - Jules Verne, Journey to the center of the Earth. A physician and medicine man, and when that doesn't work out? Bodies burn and bury easy. He has the tools for both of these vocations, though its quite often a ruse for his foul experiments on the freshly dead, and if he can manage it, the still living.
Grim connections You know where to find hassel free access to fresh corpses necessary for your experiments, and how to move them around without drawing too much attention.
A doctor is often driven by the search for knowledge. Some doctors seeks the knowlege for good, others for evil, many more just for the sake of progress.