I don't have a whole lot to add to this but thought I'd throw some things in.
A local paper, Westwood, has the shooter's home address as 1690 Paris Street, which is about 4 miles from the theater. So shooter (James Holmes) is very likely a low-income white (identified as white in news reports) who spent a lot of money preparing for this; Kevlar vest, tear gas, four weapons.
The linked article has a Google street view of the shooter's residence; it is an unremarkable apartment building.
Here is the Zip Skinny comparing that zip code (80012) to the nearby zip codes. As you can see it is a poorer neighborhood.
The mall at which the shootings took place is not a high end mall. Anchor stores are Dillard's, Macy's, Sears, and Penny's.
My stepson wanted to go to the DKR last night but couldn't get tickets. He would have been in a different theater if he had ... but this was still scary news to wake up to.
Praying for all involved.