The jury took 14 hours to reach its sentence. It was the first time a federal jury had sentenced a terrorist to death in the post-Sept. 11 era, according to Kevin McNally, director of the Federal Death Penalty Resource Counsel Project. Tsarnaev’s action was considered “a political crime designed to intimidate and coerce the United States,” said Carmen M. Ortiz, the United States attorney for Massachusetts. Prosecutors had portrayed Tsarnaev as a jihadist who sought to kill innocent Americans in retaliation for the deaths of innocent Muslims in American-led wars in Iraq and Afghanistan. Media from Russia reported that when informed of the verdict, Mr. Tsarnaev’s father, Anzor, exhaled and hung up and then turned off his cellphone.