Lead defense attorney Judith Clark, who said during opening statements last month that Tsarnaev was guilty of all 30 federal crimes charged against him, contended her closing argument that the young man had been under the influence of his older brother, Tamerlan, who she said planned the bombing.
“Tamerlan did that,” Clark told the jury.
“We need to understand who was leading and who was following,” she said, according to the Reuters news service.
Clarke’s unusual defense is aimed at persuading jurors to spare Dzhokhar Tsarnaev’s life, since several of the charges against him carry the possibility of the death penalty.
If the jury votes to convict Dzholkhar Tsarnaev, it will then decide whether he deserves death or a sentence of life in prison without possibility of parole.
Prosecutors seeking the death penalty sought to paint a far different picture of Dhokhar Tsarnaev, who they said was an active participant who believed that the marathon bombing would be some retribution for U.S. military attacks on predominantly Moslem countries.
“He wanted to awake the mujahedeen, the holy warriors,” Assistant U.S. Attorney Aloke Chakravarty said of Dzhokhar Tsarnaev.
“He wanted to terrorize this country; he wanted to punish America for what it was doing to his people,” Chakravarty said.
Dzhokhar Tsarnaev also is charged in the murder of a Massachusetts Institute of Technology police officer, Sean Collier, three days after the bombing as the brothers were trying to escape capture.
“There is no excuse, .no one is trying to make one,” Clarke said.
“Planting bombs at the Boston Marathon one year and 51 weeks ago was a senseless act,” she said.
Prosecutors showed surveillance videotape of the crowd near the race finish line that showed Dzhokhar Tsarnaev standing with a backpack outside the Forum restaurant on Boylston Street.
Moments later, prosecutors said, the second explosion of the afternoon killed 8-year-old Martin Richard, 23-year-old exchange student Lingzi Lu and restaurant manager Krystle Campbell.
“These were political choices,” Chakravarty told the jury, saying Dzhokhar Tsarnaev had copies of an al-Qaida magazine on his home computer.
“He was making a statement; an eye for an eye,” Chakravarty said.
Dzhokhar Tsarnaev attended Monday’s court session just as he had every other day of the trial, sitting silently at a defense table.
