Follow @AnneMostue on Twitter for live updates from the courtroom. 

A jury is starting its first day of deliberations Wednesday on the trial of a friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev. Robel Phillipos is charged with lying to federal investigators in the days after the bombings.

Phillipos, 21, listened intently but did not show emotion during closing arguments. The federal prosecutor listed what she said were things he lied about to FBI investigators:

His defense attorney argued in closing statements that Phillipos’ friends were speaking Russian and he was unsure what they were doing. His attorney also said Phillipos had been smoking marijuana for 14 hours before he was interviewed by FBI agents. The attorney compared them to “wolves, waiting” to interrogate Tsarnaev’s friends.

Daniel Medwed, a law professor at Northeastern University, says the marijuana defense could sway the jury either way, "On the one hand, the jury could excuse his statements to the FBI based on the idea that it’s quite reasonable that the marijuana might affect his memory and his comprehension of the questioning and his ability to respond. On the other hand, the jury could hold his marijuana use against him.”

Phillipos, who grew up in Cambridge and went to high school and college with Tsarnaev, was interviewed for hours in the days after the Boston Marathon bombings. He did not take the stand in the trial. Phillipos is charged with two counts of lying to investigators  and faces up to 16 years in prison.