There's roughly 200 doctors convicted every year in the U.S. alone of criminal 'patient abuse or neglect', for data compiled between 1988 and 2026 [1]. While I'd prefer to cite the 'patient abuse' figure since 'patient harmer' is the most equivalent behavior to 'firefighter arsonist' (both cause the problem they treat), I think it's worth remembering that human beings — regardless of their profession — have a slim but non-zero chance of deciding to create problems that give them professional satisfaction to solve.
[1] https://plaindiscipline.com/action-type/conviction-patient-a... —