There wasn't, as far as I can tell, any mainstream media reports about Sunil being involved in the Boston marathon bombing, the only accusations were from redditors tricked by a faked police scanner report that supposedly IDed him as the bomber.

Edit: A relevant comment from a journalist regarding the situation: http://www.reddit.com/r/blog/comments/1cvb9b/reflections_on_...

    As a member of the reddit community, I was really disappointed with the 
    Sunil Tripathi debacle. D'you know why his name wasn't widespread in 
    the press as a suspect? Because generally we like to ask police for 
    confirmation on a suspect name before publishing it.

    If reddit users want to act like journalists, they should follow the same 
    procedures. You're not special just because it's "the internet"