I heard a theory on the Internet that there were two shooters

because the shots were louder and less loud from the same location

on the street.

If you look at the holes in the windows on the building

you will see that there is a corner of the building 

jutting out between the holes.

This explains to me why you might notice two different

shot volumes from the same location on the street.

Possible motives:

1 Life long secret agent paid well,worked

for nation state to cause disharmony in US.

Was willing to die for the cause.

Could be one of many states. Follow the money.

2 Took 64 years of crap and was full to the brim

drugs will alter decision making.He held in his anger

and then exploded because he didn't find a good outlet.

He thought everyone was an asshole.

But not everyone is.

3 He recently joined a terrorist organization.

Due to 2 above.

4 He had a secret political motivation and believed

the ends justify the means.

But the ends reflect the means.

5 He watched to much news, refer to 2 above.

6 Something went wrong in his brain.

7 He was a life long criminal that didn't

care about almost any other people and never got caught.

Went out with a bang.

Question:

Why did Stephen Paddock dress the way he did in public?

Most probable answer:

Didn't care about impressing people,

and more importantly, dressing that way lowers the chance

of being hassled or robbed.