Where's the justice?

[kılıç_mehmet]

Two non-Christians are going about their life. They have a dispute that ends in one being killed by the other. The one left alive in his/her later years becomes a Christian.

Now, according to theology, that person is going to heaven. The one who was killed is eternally getting punished. Where's the justice? How does the killer go unpunished like that?

Well, I don't know where the injustice lies. They have both drawn their weapons with the intent of shedding eachother's blood, yes?
Even if, the christian religion offers salvation for those who accept christ. Their past sins are washed away. This is a major point in christianity.