Complex sentence: Gerstein returns home and gathers all his evidence that document the Nazi atrocities and takes them to the allies, despite accepting his evidence he is still arrested and after reading the charges against him he is found hanged in his cell.
Split into simpler sentences: Gerstein returns home and gathers all his evidence that documents the Nazi atrocities and takes them to the allies. Despite accepting his evidence he is still arrested and after reading the charges against him he is found hanged in his cell.