There is an Old Testament principle that applies in the case of defending ones property: “If a thief is caught breaking in at night and is struck a fatal blow, the defender is not guilty of bloodshed; but if it happens after sunrise, the defender is guilty of bloodshed” (Exodus 22:2–3).
In the case of a night-time attack, the Law granted the homeowner the benefit of the doubt that, apart from the darkness and confusion of the attack, he would not intentionally use lethal force against a thief. Even in the case of self-defense against a thief, a godly person was expected to try to restrain the assailant rather than immediately resort to killing him.
The Old Testament makes it clear that the life (of humans and animals) is in the blood (Leviticus 17:14; Deuteronomy 12:23) and under the Mosaic Law the punishment for taking the life of a human being is death (Leviticus 24:17).
Under the Mosaic Law an individual who committed manslaughter, or the unintentional and accidental killing of a person, could find sanctuary in any of the six designated cities of refuge throughout the land of Israel (Numbers 35:10–15, 22–25; Deuteronomy 19:4–6; Joshua 20:1–6). But the person guilty of shedding the blood of another was himself at risk of being avenged should he leave the city of refuge. Even manslaughter (unintentional and accidental killing) breaks God’s laws.
The principle is clear - no one should be too quick to use deadly force against another, even someone who means to do him (or his family) harm.
In the situation you describe the person who takes the life of another will be judged by God, just as the person who commits rape or murder will be judged by God. Regardless of right and wrong, any person who takes the life of another person has sinned and will answer to God for what they have done.
With regard to who bears the responsibility of sending someone to hell, people go to hell because of their own sin, which they freely choose. James 1:14-15 speaks of pre-meditated sin: “each person is tempted when he is lured and enticed by his own desire. Then desire when it has conceived gives birth to sin, and sin when it is fully grown brings forth death.”
John 3:18 explains in the simplest terms who will go to heaven and who will go to hell: “Whoever believes in him is not condemned, but whoever does not believe stands condemned already because they have not believed in the name of God’s one and only Son.” So, those who go to hell are specifically those who do not believe in Jesus’ name. Source: https://www.gotquestions.org/who-will-go-to-hell.html
As Christians we all have a responsibility to share the gospel with others – the great commission is not an option! In a crisis situation, such as you describe, prayer in the powerful name of Jesus may be a deterrent. Indeed, miracles have been known to happen where the hand of an assailant has been stayed by divine intervention. The burden of who goes to hell rests squarely on the shoulders of the individual. Only remember that the shedding of blood breaks God’s commandments, even if done in self-defense.