BOSTON (AP) — A friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev (joh-HAHR' tsahr-NEYE'-ehv) has taken the witness stand at a hearing on his own motion to suppress statements he made to authorities.

Dias Kadyrbayev (DY'-us kah-dur-BY'-ehvz) is accused of removing items from Tsarnaev's dorm room at the University of Massachusetts-Dartmouth several days after the April 2013 bombings.

Kadyrbayev began testifying Monday afternoon. That was after a linguistics expert testified she believes it is "highly unlikely" Kadyrbayev was proficient enough in English to understand his rights.

A judge ruled last month that Kadyrbayev would have to subject himself to cross-examination by prosecutors for the judge to consider his written affidavit.