Amnon in Easton's Bible Dictionary

faithful. (1.) One of the sons of Shammai, of the children of Ezra (1 Chr. 4:20; comp. 17). (2.) The eldest son of David, by Ahinoam of Jezreel (1 Chr. 3:1; 2 Sam. 3:2). Absalom caused him to be put to death for his great crime in the matter of Tamar (2 Sam. 13:28, 29).

Link: https://bible-history.com/eastons/A/Amnon/