Punishments were Inflicted by Order of Kings
Source: TTT
2 Samuel 1:13–16
And David inquired of the young man who had brought him the report, “Where are you from?” “I am the son of a foreigner,” he answered. “I am an Amalekite.” / So David asked him, “Why were you not afraid to lift your hand to destroy the LORD’s anointed?” / Then David summoned one of the young men and said, “Go, execute him!” So the young man struck him down, and he died.
1 Kings 2:23–46
Then King Solomon swore by the LORD: “May God punish me, and ever so severely, if Adonijah has not made this request at the expense of his life. / And now, as surely as the LORD lives—the One who established me, who set me on the throne of my father David, and who founded for me a dynasty as He promised—surely Adonijah shall be put to death today!” / So King Solomon sent the order to Benaiah son of Jehoiada, who struck down Adonijah, and he died.