Boston Bomber case: Kavanaugh, Kagan clash in rare testy exchange over mitigating evidence

The Supreme Court is considering whether to uphold an appeals court's decision to overturn Boston Bomber Dzhokhar Tsarnaev's death sentence.

Justices Sonia Sotomayor and Elena Kagan grilled government lawyer Eric Feigin specifically about mitigating evidence the defense was not allowed to introduce: That Tamerlan may have been involved in a jihad-related triple-murder two years before the Boston Bombing. This evidence was relevant, the defense said, because it bolstered their argument that Dzhokhar would not have committed the bombing if it weren't for his domineering older brother's influence. 

The government and district court argued that the evidence on those murders was not particularly strong. But Kagan asked Feigin to "assume" that the evidence was strong: What should the district court have done then, she asked.