Does the son inherit from his mother who killed his father, knowing about the crime and not preventing it? And does the murdering wife inherit?

The general consensus among scholars is that a deliberate killer inherits nothing from the person he killed, based on the hadith: "A killer does not inherit anything." This is also because allowing a killer to inherit would lead to an increase in killings. This ruling applies to anyone who committed the murder or assisted in it. Thus, a wife who killed her husband does not inherit from him. However, a son who did not participate in the killing is not deprived of his father's inheritance and also inherits from his mother, regardless of her being a killer.