We are learning that the man who tried to assassinate Former President Donald Trump surveyed the site with a drone beforehand.

Sources familiar with the matter told NBC News that Thomas Crooks flew a camera drone over the rally site just hours before Donald Trump spoke.

The overhead view of the site helped Crooks plan his attack.

It is common practice for the Secret Service to ban drones over areas they are securing.

Although it is unclear if that happened for the rally in Butler, Pennsylvania.