An angel of mercy or angel of death is a rare type of criminal offender (often a type of serial killer) who is usually employed as a caregiver and intentionally harms or kills people under their care. The angel of mercy is often in a position of power and may decide the victim would be better off if they no longer suffered from whatever severe illness is plaguing them. This person then uses their knowledge to kill the victim. As time goes on, this behavior escalates to encapsulate the healthy and the easily treated.