evidence from tsarnaev's dorm room after the attacks including a backpack containing fireworks and a laptop. tazhayakov and kadyrbayev, both from kazakhstan, were staying in the u.s. on student visas. the only issue -- tazhayakov is no longer a student. tazhayakov returned to kazakhstan in december 2012, according to a u.s. government official, his status as a student at umass, dartmouth, was terminated the next month on january the 4th. and at this point, his student visa should have been invalidated. umass, dartmouth, took the proper steps and provided information into the appropriate system for foreign students that he was no longer registered there, officials say, but customs and border protection never got the message. when tazhayakov returned back to the united states on january 20th, he was granted entry. the department of homeland security says that it's reforming the student visa system to ensure that customs and border protection is provided with realtime updates on all relevant student visa information.