Can Jedi Kill?
Jedi defend. Yes sometimes that defense can involve eliminating an opponent. I refer you to the end of ROJ in the throne room. Luke is hiding from his father because he doesn't want to fight, doesn't want to kill him. Vader speaks "If you will not turn to the darkside, then perhaps she will." in reference to Leia. Luke then switches from not wanting to fight his father to defending Leia from his threat of the darkside.
A Jedi is more than capable of killing; he just doesn't do it without a very good reason. Jedi do not kill out of hatred or any other emotion. You must remember the code, “There is no emotion, there is peace.” They do it out of defense of another, or out of a service to the greater good. When Luke came to peace with his emotions he realized he did not have to kill to complete his goal. That was when he became a Jedi. Yes Jedi do have to kill sometimes, but they first have to seek all paths open to them. If a Jedi knowingly disobeys and breaks the code, he is seduced by the darkside.
