A lot has been written on whether donations of tainted money should be accepted. The money is tainted either because it is ill-gotten or because the donor is ethically challenged (e.g., sexual predator, history of illegal activities, etc.). Agreement is not universal. I would like to find a halachic source with clear guidance. In particular, answers to:
If the donated money saves lives (hospitals, medical research, etc.), should it be automatically accepted?
If the donated money does not save lives (synagogues, yeshivot, etc.), should it be returned or unilaterally redirected to a purpose that saves lives?
If the money must be returned, should it be returned to the donor, to its rightful owners if they can be identified, or to the authorities?
Shouldn't the donor be allowed to perform the mitzvah of tzedakah, with or without teshuvah?