Intention (niyat) leads to commitment (pukhta irada) which then leads to the act. All of these were absent in case of a child, so how could a child be punished? It is at this second stage of commitment (pukhta irada), the accountability will begin because a person reached this decision out of his freewill (irada-o-ikhtiyar) and it provides enough grounds to establish Shahdah on that person. Since murder was not committed and no damage can be shown, so it can’t be equated with sin where murder is actually done. it should belong to a lower category as compared to murder.

But at the end of the day, they both have a chance to repent and make good any damage they have caused. There is a chance that person who actually committed murder might be forgiven because of his attitude afterward and a person who had commitment to murder might go to hell because of Vanity/arrogance (Sarkashi/Istakbaar)) that he might have adopted despite having second chance by still having those strong commitments and plots for murders. He might not die a murderer, but might die as a Sarkash/Mustakbir. Therefore, we cannot always account for these countless intricacies surrounding a human being.