The two men accused of the Washington sniper killings have met for the first time since their arrest last year.
Malvo was 17 when he was arrested
Lee Boyd Malvo, 18, and John Allen Muhammad, 42, face charges relating to a spate of sniper attacks around the Washington DC area last October in which 10 people died and three were wounded.
On Wednesday Mr Malvo, who was 17 at the time of the killings, was called to a pre-trial hearing for Mr Muhammad's case, which is due to start on 14 October.
Mr Malvo, whose own trial is due to start on 10 November, invoked his Fifth Amendment right against self-incrimination and refused to answer questions.
Earlier on Wednesday, Mr Muhammad's defence lawyers complained that he was questioned improperly by investigators in Maryland after his arrest and requested that some material be excluded from the trial.
Circuit Judge LeRoy Millette rejected the defence motion and said Mr Muhammad's statements could be used.
John Allen Muhammad faces the death penalty
But prosecutors apparently agreed to exclude the material.
Judge Millette also rejected a motion seeking to bar the death penalty on one of two capital-murder charges facing Mr Muhammad.
Defence lawyers had argued that the terrorism law under which Mr Muhammad is charged is written in such a manner that the maximum penalty should be life in prison.
Mr Malvo's lawyers had objected to him appearing in court, arguing that he could have asserted his Fifth Amendment rights
through a written affidavit.
Prince William County Commonwealth's Attorney Paul Ebert
will now submit to the judge a list of questions he wants
to ask the teenager.
If they are deemed potentially incriminating,
Mr Malvo can again cite the Fifth Amendment.
One of his defence team, Craig Cooley, said the two men appeared to make some eye contact during the hearing.
Mr Malvo's legal team says he was brainwashed by
Mr Muhammad and Mr Cooley said the teenager had "a degree of nervousness... if not fear" going into the hearing.