I read this:

http://globalgrind.com/news/411-sunil-tripathi-missing-brown...

which seemed legit, until I read the source:

http://www.punditpress.com/2013/04/sunil-tripathi-informatio...

which seems really sketchy. I've seen it a bunch of places, making it seem like it was confirmed but people are now refuting it:

https://twitter.com/BuzzFeedAndrew/status/325176638537076736

I hope for his family's sake it's not him.

Edit: And it seems confirmed that it isn't: http://hosted2.ap.org/CAANR/e109e277e48c4e219e07a1d4710177b3...

They're saying it was two Russians now on WCVB. Not sure how credible that is yet. On the other hand, the mere existence of that information on Punditpress is a good reason to doubt its accuracy.

Update: It's semi-official now (on WCVB): the two men were apparently from Chechnya.