Finish Line

Prosecutors have spent the last month presenting some haunting evidence against admitted Boston Marathon bomber Dzhokhar Tsarnaev, which seems to go beyond what the government needs to do to convict him and begins to build the case that he should be sentenced to death. Boeri and Cullen discuss Day 15 of the trial, in which the government called its final witness to tell the jury of the horrific death of 8-year-old Martin Richard near the finish line.

The enduring images from the 2013 Boston Marathon bombing are of mass carnage - of innocent people with their limbs blown off by two pressure-cooker bombs placed near the finish line. Boeri and Cullen discuss Day 14 in the trial of Dzhokhar Tsarnaev, when the prosecution demonstrated that those bombs were intended to cause maximum death and destruction.

Every time you send a text message, swipe a credit card, use a GPS system or go into a public building, you leave a digital record of your activities. And if you're 19 years old, those records are likely to be extensive. Boeri and Cullen review the data dump the prosecution unloaded on Dzhokhar Tsarnaev and his deceased older brother, Tamerlan, in Day 13 of the trial.

Less than a month before the Marathon bombing, Dzhokhar and Tamerlan Tsarnaev rented two 9mm handguns for target practice at a shooting range in New Hampshire. The weapons were the same caliber as the gun used to kill an MIT police officer three days after the bombings. Boeri and Cullen discuss the evidence that continued to pile up against Dzhokhar in Day 12 of the trial.

The prosecution and defense agree - Dzhokhar Tsarnaev was involved in the bombing at the Boston Marathon, the killing of MIT police officer Sean Collier, and the shootout with police in Watertown. So on Day 11, the prosecution posed this question to its expert witness: what turns a seemingly average teenager from Cambridge into a violent radical, intent on and capable of deadly acts of terrorism? Boeri and Cullen discuss the evidence presented.

In the government's case against admitted Boston Marathon bomber Dzhokhar Tsarnaev, they want to prove that he is a radical jihadi, and that's why he planted a bomb near the finish line in April 2013. Boeri and Cullen discuss Day 10 of the trial and the digital trail Tsarnaev left behind, presented by the prosecution as evidence of his radicalization.

As moving and emotional as the stories in this trial have been, the successful prosecution of a criminal in a death penalty case depends not just on testimony, but on physical evidence. In Day 9, the prosecution turned its focus to some of that evidence - including two bloody gloves.

Any hope the defense has of saving Tsarnaev's life is in convincing the jury that he was just a deadbeat, pot-smoking college student, under the sway of his older brother Tamerlan, the real jihadi. A demonstration of what they're up against - say Boeri and Cullen - came in Day 8 of the trial, with the first testimony from one of Tsarnaev's old friends, Stephen Silva.

Three days after the Boston Marathon bombing, authorities searched the city in an epic manhunt for the Tsarnaev brothers. That led to a shootout in the Boston suburb of Watertown, the death of the older brother, Tamerlan, and the capture of his younger brother, Dzhokhar. Boeri and Cullen recount the chaos of that shootout and the aftermath - the focus of testimony in Day 7 of the trial.

When we talk about the Marathon bombing, we talk about the three people who were killed that day. But there was a fourth murder, three days later - of an MIT police officer. In Week 2, the trial turned to that shooting and the carjacking that followed. Boeri and Cullen recap the testimony of the carjack victim, who gave a riveting account of his hours as a captive of the Tsarnaev brothers.

In the second week of the trial, attention in the courtroom has turned from what happened to why. Boeri and Cullen discuss the defense's focus on Tsarnaev's Twitter feed, and on a nine-minute surveillance video showing Dzhokhar and his older brother Tamerlan walking down Boylston Street on Marathon Day — and why Tamerlan appearing to lead the way could be so meaningful.

The iconic photo from the Boston Marathon bombing is a determined man in a cowboy hat pushing a young man in a wheelchair whose legs have been blasted off. That young man took the stand as testimony continued in Day 2 of the Tsarnaev trial. Boeri and Cullen react to that testimony, and that of Bill Richard, the father of 8-year-old Martin, who was killed in the attacks.

As the trial of Dzhokhar Tsarnaev opens, Boeri and Cullen talk about the defense's concerns over jury bias, with the trial being held in Boston, and what changed when this became a federal death penalty case. They also look ahead - to what could be the most explosive moments of the trial.