What clinical term does Amir refer to Assef

From the text:

Years later, I learned an English word for the creature that Assef was, a word for which a good Farsi equivalent does not exist: "sociopath."

Sociopath: Psychopath and sociopath are often used interchangeably in common speech to describe a person who is pathologically prone to criminal or violent behavior and who lacks any regard for the feelings or interests of others and any feelings of remorse or guilt for his crimes.