In an 800-plus-page final report released Thursday, the House panel investigating the Jan. 6 attack on the Capitol detailed the conclusions of its extraordinary 18-month investigation into efforts to overturn the 2020 presidential election. But a number of key questions about what transpired on Jan. 6, 2021, and the broader effort to overturn the 2020 presidential election still remain unanswered due to missing evidence, uncooperative witnesses and other factors.