i agree with you, he was trespassing at least.
I don’t buy the “ he was interested in architecture” bs.
That being said, shooters should not have put themselves in the mix.
In many states, laws require there be a warning, either by a sign or warning by the property owner, that you aren’t allowed to be on property before you can be convicted for trespassing on the property.
All four involved acted stupidly. But this is what happens when things go south when the police can’t manage to maintain law and order.