Defending oneself by any means necessary?

I am aware that one is allowed to use lethal force to defend one’s life against a malicious attacker, if there is no other way to defend oneself. (For example if someone wields a weapon with clear intent to kill you.)

The question is: “If someone unknowingly and unintentionally puts you into mortal danger, how far can you go in defending your life”? If there is no other way, are you allowed to use lethal force? I looked at the catechism, but did not find any guidelines.

Thank you for your time.

The same criteria is applied whether the one inflicting the potential harm is doing so intentionally or unintentionally. We must only use lethal force in self defense if it is absolutely necessary to defend another life, however the intention of the one creating the danger is not relevant to the actual danger involved.

Obviously when someone is unintentionally creating a danger, we probably have more options available to us to explain that they are creating a danger or to act in a way that doesn’t use lethal force. However, if that remains the only viable option then it is permissible.

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