First he killed King Amalickiah.
Teancum stole privily into the tent of the king, and put a javelin to his [Amalickiah's] heart. Alma 51:34
And then King Ammaoron
Teancum ... was exceedingly angry with Ammoron ... And it came to pass that Teancum in his anger did go forth into the camp of the Lamanites, and ... cast a javelin at him, which did pierce him near the heart. Alma 62:35-36