The FBI has released footage of Aaron Alexis at the Washington Navy Yard on the day of his killing spree last week.

It’s a terrifying look into his actions, from the moment he drives into the yard to the point where he can be seen carrying a Remington 870 shotgun through the halls.

The FBI also released the timeline of events that played out that day, beginning with Alexis arriving at the yard at 7:53 a.m. and lasting until he was shot and killed by officers at 9:25 a.m. In addition, the agency has put out photos with Alexis at the yard.

Alexis, 34, killed 12 people during his rampage and left nearly two dozen injured.

[FBI]