Finish Line

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.