In the episode Outlaws (S01E16), Charlie and Sayid discuss Ethan Rom, saying
SAYID: You killed a man.
CHARLIE: A man who killed one of us, who kidnapped Claire, who strung me up and left me for dead. He deserved to die. I'd do it again in a minute. Pardon me, if I'm fresh out of bad feeling.
Ethan did kidnap Claire, left Charlie for dead, and possibly attacked Jack, but I don't recall him killing anyone at this point, and his wikia page doesn't mention anything.
Who does Charlie think Ethan killed?