<p>Some have created crappy disinfo memes to fit their conspiratainment complex agenda

http://i.imgur.com/I5XIp5M.jpg

http://www.skilluminati.com/research/entry/the_conspiratainment_complex/

They were officially National Guard Civil Support Team members.

http://www.defense.gov/news/newsarticle.aspx?id=119805

CST's are WMD first responders

https://en.wikipedia.org/wiki/Civil_Support_Team

Here is another state's CST the same black and tan uniform seen on the streets of Boston.

http://www.idaho.ang.af.mil/news/story.asp?id=123259663

Here are their movements in the first 10 minutes post bombing. Much speculation rests on their movements in these first moments, arguing that two CST members were very close to the bomb site.

http://www.nbcnews.com/video/nbcnews.com/51577004#51577004

Notice their distinct SUV arrive.

http://stowaway2.blogspot.com/2009/09/stowaway-max-helps-civil-support-team.html

They also have a truck similar to this

http://www.moguard.com/05-09-11-7thcst.html

Here they are at the same time period, in pictures</a>, courtesy of /u/dahvee on reddit. Again, note the badge patches on their jackets, and how they start clearing the area under the bleachers for suspicious objects.

http://imgur.com/a/YrTOK

One of the the trio that was spotted behind the crowd can be seen on the left in this group picture.

He is readily identifiable as part of the Massachusetts NG CST.

http://states.ng.mil/sites/MA/News/Pages/Civil%20Support%20Team%20hosts%20unique%20speaker%20event.aspx

With this information in mind, the one man's hat likely references Chris Kyle, the best selling navy seal author.

http://www.amazon.com/Chris-Kyle/e/B005DONBU4/ref=sr_ntt_srch_lnk_1?qid=1366290667

<p>This hat can be bought on ebay or is readily available in their online shop. The horizontal blur in the skull is unique to these Craft Int. hats. It does not resemble the vertical character of the actual Navy Seal logos, which are numbers or blank.

http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313.TR9.TRC2&_nkw=chris+kyle+hat&_sacat=0&_from=R40

http://www.511craft.com/All-Products/Craft-Logo-Wear/Craft-Hat.html

I would also point out that Craft Int offers regular civilian training courses. This hat does not, by definition mean this individual would be part of an elite force.