[Right_Wing_Madman]

The spectator video of Crooks first crawling on the roof appears to show a male individual wearing long white pants...In the death photo, Crooks is obviously wearing short pants.

This is a rather important detail, isn't it?

Other video footage shows Crooks walking around the building with his rangefinder in long white pants three hours before the shooting.

The dead guy on the roof isn't Crooks. Not only is he wearing shorts, he has a different face and body type.

[Karl Spooner]

walking around the building with his rangefinder in long white pants

I was wondering the same thing 4 days ago when I made this. It looks to me like they come down a little below his knee. It's more of the movement of the pants rather than the color differential more than anything else, imo, and decided not to make a big deal about it.

[zeestephen]

I have only seen photos or videos of the dead guy with the face and most of the body blurred out.

I am no help with the ID.