Penalty Phase of Boston Bombings Trial Starts April 21

The sentencing phase of the Boston bombings trial, which will condemn convicted killer Dzhokhar Tsarnaev to death or life imprisonment, will begin on April 21, the judge ruled Friday.

It will come the day after the city holds the 2015 edition of its popular marathon, which Tsarnaev and his elder brother Tamerlan attacked with twin pressure-cooker bombs on April 15, 2013.

The bombs killed three people and wounded 264 others in the deadliest attacks on U.S. soil since the 9/11 al-Qaida hijackings.

A 12-person jury on Wednesday unanimously convicted 21-year-old Tsarnaev on all 30 counts related to the attacks, the murder of a police officer, a carjacking and a shootout while on the run.

Judge George O'Toole granted Tsarnaev a two-week delay on the start of the penalty phase to allow the defendant to resolve logistical issues with a number of potential witnesses. 

He instructed the jury to return to court for brief instructions on scheduling and logistics on April 14.

Seventeen of Tsarnaev's convictions carry the death penalty under federal law, and the penalty phase is likely to prove far more contentious than the initial one-month phase of the trial.

No one has been executed in the state of Massachusetts since 1947, and Catholic bishops this week reiterated their opposition to the death penalty under any circumstances.