Prosecutors and defense attorneys in the
At the government's request, "special administrative measures" were placed on Tsarnaev that permit him little contact with the outside world, lest he try to communicate with Islamic extremists.
Prosecutors have said that while the
But defense lawyers maintain in court papers made public Monday that "there is no reason to believe" either of these scenarios.
They rebutted the notion that the sisters would "attempt to engage in terrorist tradecraft" while meeting with their brother.
Defense lawyers also complained that at one meeting with their client, an FBI agent monitoring the conversation was "needlessly intrusive and interfered."
They say the restrictions on Tsarnaev should be lifted because they are interfering with efforts to meet privately with him to plan a legal defense strategy and prepare for trial.
Tsarnaev, who potentially faces the death penalty, was arrested several days after the April 15, 2013, bombings that killed three people and injured more than 260 others when two pressure-cooker explosives detonated at the finish line of the annual marathon.
His older brother, Tamerlan, was killed in a shootout with police. Authorities say the pair committed the worst terrorist assault in this country since the Sept. 11, 2001, attacks.