President Donald Trump met with top military officials and gave his approval to activate the D.C. National Guard three days before he encouraged a mob of angry protesters to take their grievances to the U.S. Capitol.

A Pentagon memo released Friday offers these insights, as well as the first detailed timeline of the bungled law enforcement response to Wednesday’s insurrection.

The timeline shows that the planning started at least as far back as Dec. 31 and included discussion with select Cabinet members of the potential need for Pentagon reinforcements.

But it also leaves many questions unanswered, including why the U.S. Capitol Police declined repeated offers of assistance from military officials and the full extent of how much Trump knew about the security planning or was involved in decision-making.

The memo, first reported on by NBC News on Friday evening, presents a limited account of the days before the insurrection, and reports have questioned the completeness of the Pentagon’s version of events and the effectiveness of its planning and response. But the memo may well provide a partial roadmap as legislators call for an investigation into how pro-Trump protesters breached the Capitol in a riot that left five people dead, including one Capitol Hill police officer. Three officials who supervise the force have already submitted resignations.

Here’s what we know so far, and what we don’t.