1. It is possible to find your grandfather’s bones. You can go to the prison where he was. If the prison has been moved, you can go to the local Justice Department and find the archives from that year. It is possible to find it. The remains fulfill your wish.
2. Hearsay is not enough. Only by finding the archives and insiders from that year can we find out the real situation. However, it takes too long and it is very difficult.
3. A prisoner in custody escaped from prison and was shot to death. This is in compliance with regulations. If this is the case, there is no need for you to appeal.
To tell the truth, for your reference, I wish you good luck.