I just looked at the photo of the ladder on Daily Mail.
I counted 10 ladder rungs, typically that is a 10-foot ladder. The ladder does not look to be an extension ladder, Maybe a folding ladder, but does not look like that either.
And the building looks to be about 12-14 feet tall, with she connecting ‘hallway’ at 10 feet.
This 5-foot ladder report is suspect to me. Where is it, if it is not ‘my’ 10 footer.
And purchased 50 rounds? 223/5.56 is often in 20-round boxes. so that is 20. 40. or 60. Maybe the store has a ‘50 round special’?
But if he is a ‘lone wolf’, then he did it all himself, as reported about the ladder and ammo. (/Suspicion)