http://www.timesfreepress.com/news/local/story/2015/jul/21/obama-orders-flags-flown-half-staff/315730/

And this is for those that need to understand the Half Mast Etiquette and Principles although I do support them at Half Mast in this case:

http://www.usflag.org/nff.half.staff.html

Just because he didn't do it the second they were shot doesn't mean a darn thing. There is a process to go through before taking such action and he did just that. It wasn't just Obama, either, it was everyone but, ONLY THE MAGGOTS FOUND FAULT IN ONLY OBAMA:

http://www.nydailynews.com/news/politics/boehner-orders-capitol-flags-half-mast-chattanooga-dead-article-1.2298700

Excerpt:

Congressional leaders as well as the White House have faced growing criticism for not flying flags at the two buildings to acknowledge the four Marines and one Navy sailor who died last week after a Kuwaiti-born gunman attacked two military sites in Tennessee.

Finally, here's Snopes that get's it right every time and please check the comments out and I like Ken's common sense:

http://m.snopes.com/2015/07/19/chattanooga-flags-half-staff/


Ken says:
2015-07-19 at 9:09 pm
Because sadly, if we lowered the flags every time someone serving in our military died, they’d never go back up. And it would become the norm. We’d start lowering the flags to quarterstaff(?) for especially tragic events, and be right back here having this same debate.