A friend of the Boston Marathon bombing suspect lied repeatedly to investigators before eventually confessing about his activities in the days after the attack, a federal prosecutor said on Tuesday.
Over the course of a federal trial, defense lawyers for Robel Phillipos have argued that the 21-year-old was too high on marijuana to remember what he did the night of April 18, 2013, when prosecutors say he and two other men removed a backpack containing empty fireworks shells from the dorm room of bombing suspect Dzhokhar Tsarnaev at the University of Massachusetts-Dartmouth.
Phillipos later confessed to the FBI, though defense attorneys have argued that his admission was due to coercion by FBI agents.
Reutersreportsthat during closing arguments in U.S. District Court on Tuesday, Assistant U.S. Attorney Stephanie Siegmann said Phillipos lied to investigators in four interviews with FBI agents before finally telling the truth in a fifth.
"This case is about a person who lied, not a person who didn't remember," she said. "Someone who lied to protect himself and his friends because of the inconceivable thing they had done."
The defense team has presented witnesses including college friends of Phillipos, who testified that he had smoked copious amounts of marijuana the night of the alleged visit to Tsarnaev's dorm room.
An expert on marijuana abuse, Dr. Alan Wartenberg, testified the drug could have impaired Phillipos' cognitive abilities and memory.
The attorneys also summoned former Massachusetts Governor Michael Dukakis, a friend of Phillipos' family, who said the student was "so confused he didn't know what he had said" to the FBI.
Earlier, FBI agents said Phillipos initially denied visiting Tsarnaev's room and produced a written statement from Phillipos in which he admitted going to the room.
Prosecutors say Phillipos, a student from Cambridge, Massachusetts, and two other Tsarnaev friends went to Tsarnaev's dorm room three days after the attack, following the FBI's release of photos of the suspected bombers.
If convicted, Phillipos faces a penalty of up to 16 years in prison for the charge of lying to investigators.
Another Tsarnaev friend, Azamat Tazhayakov, was convicted in July of obstruction of justice for taking a backpack containing fireworks from the dorm room and another, Dias Kadyrbayev, pleaded guilty to obstruction in August.
The marathon attack, the worst on U.S. soil since the Sept. 11, 2001, airplane hijackings, killed three people and injured more than 260 when a pair of homemade bombs exploded near the crowded finish line of the Boston Marathon on April 15, 2013.
Tsarnaev, 21, is awaiting trial on charges that carry the death penalty. His brother Tamerlan was killed in a shootout with police three days after the bombing.
Reuters contributed to this report.