Photos from a Zero Hedge post (4/18/2013):
2 suspects in the same shot:
Somewhat clearer photo of the 2nd suspect with a white cap:
So they were wearing black jackets and had backpacks, walking in generally the same direction at several steps apart. (Like many others?)
There seem to be several other people captured by videos or photos who also wear black jackets and heavy backpacks, but FBI says "other photos will not be deemed credible", as Infowars reports:
Photos from Infowars, men with big backpacks, talking to someone:
and the peculiar logo mark on their hats:
The government denies there was any training operation at the Boston Marathon.