Three people were killed and 264 others wounded in the twin blasts at the city's marathon, the worst attack in the United States since the September 11, 2001 attacks on New York, Washington and Pennsylvania.
Government prosecutors portrayed the Muslim immigrant, who became a US citizen in 2012, as a callous terrorist who carried out the bombings to bring holy war to the northeastern US city and punish America.
Tsarnaev's defense attorneys admit that he took part in the attack, but have sought to portray him during the trial as a helpless accomplice, bullied or manipulated into participation by his more radical elder brother.
Seventeen of those charges carry the possibility of the death penalty under federal law.
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Judge George O'Toole instructed the jury as to the law and evidence, and dismissed six alternates, leaving 12 men and women who will decide the case.
"With that jurors we ask you now to withdraw to deliberate upon the evidence and return with your verdict," he said.
But with just minutes to go until the end of the working day, he ordered them to return at 9 am (1300 GMT) today to begin deliberations.
Prosecutors spent four weeks building their case, calling 92 witnesses in an effort to paint Tsarnaev as an active and willing bomber alongside his elder brother, who was killed while on the run.
"He wanted to terrorize this country. He wanted to punish America for what it was doing to his people," assistant US attorney Aloke Chakravarty told the court in an emotional closing statement yesterday.