Does sin attach to one who kills a married fornicator or a killer without referring to the matter to the judge?

It is not permissible to kill the married fornicator (muḥṣan) because the implementation of the ḥadd (punishment) is the right of the ruler, and it is not permissible for individuals to carry it out due to the strife and chaos it would cause. Killing him without lawful evidence necessitates qiṣāṣ (retaliation). If an individual kills him after adultery has been proven and ruled upon, then that individual is sinful and deserves taʿzīr (disciplinary punishment) for usurping the authority of the Imam, but there is no qiṣāṣ against him. The killer is not liable for the apostate, the one who abandons prayer, or the married fornicator; rather, he is disciplined for overstepping the authority of the Imam, because killing in such a case is an usurpation of the authority of the ruler and a cause of chaos. Similarly, it is not permissible to kill a man found killing another; the killer's blood is inviolable for anyone other than the guardians of the victim's blood.