Prosecutors on Tuesday began their case to sentence convicted Boston Marathon bomber Dzhokhar Tsarnaev to death with an emotional gut-punch to the jury as survivors described the toll of the April 15, 2013, attack that killed three people and injured 264.
Tsarnaev, a 21-year-old ethnic Chechen, was found guilty on April 8 of carrying out the attack as well as fatally shooting a police officer as he and his older brother, Tamerlan, prepared to flee three days later.
Survivor testimony, photos and video evidence took the same jury that found Tsarnaev guilty back to the immediate aftermath of the blasts, the smoky air rent by the screams of the wounded while those able to move scrambled over shrapnel-strewn sidewalks to try to aid those whose limbs the bombs had mangled.
The government's first witness, Celesete Corcoran of Lowell, Massachusetts, said she remained conscious from the moment the two homemade pressure-cooker bombs went off until she was rushed to a hospital where doctors amputated both her legs.
Prosecutors opened the trial's sentencing phase by showing the jury pictures of the four people Tsarnaev killed: 8-year-old Martin Richard, Chinese exchange student Lingzi Lu, 23, Massachusetts Institute of Technology police officer Sean Collier, 26, as well as Krystle Campbell.
Prosecutors, citing al-Qaida materials found on Tsarnaev's laptop and a note in which he suggested the bombing was retribution for US military campaigns in Muslim-dominated countries, have sought to paint him as a violent extremist.
Defense attorneys have countered that 26-year-old Tamerlan, who died following a gunfight with police hours after Collier's slaying, was the driving force, with Dzhokhar acting in a secondary role out of a sense of sibling loyalty.
Tsarnaev's lawyers opted to delay their opening statement until next week.
In an apparent effort to anticipate a likely defense argument, Nadine Pellegrini, an Assistant U.S. Attorney, argued that Tsarnaev's actions could not be blamed on his troubled family.
Pellegrini urged the jury not to give too much consideration to evidence that suggested Tamerlan had downloaded radical materials before Dzhokhar.
Pellegrini ended by showing the jury a surveillance photo she said was taken of Tsarnaev in a holding cell on the day of his first court appearance in July 2013.
In the photo, Tsarnaev is grimacing and gesturing at the camera with his middle finger, an obscene gesture.