Jurors who started their eighth hour of deliberations this morning in the terror trial of Boston Marathon bomber Dzhokhar Tsarnaev have asked the judge two key questions.

First, the panel of seven women and five men asked U.S. District Court Judge George A. O'Toole Jr. whether a conspiracy can pertain to a sequence of events over multiple days or if is it a distinct event.

O'Toole advised them to follow the evidence, while reminding them the conspiracy that led to the April 15, 2013, attack is alleged to have spanned from February 2013 to the capture of Tsarnaev and the death of his brother Tamerlan on April 19, 2013 — in other words, over multiple days.

Their inquiry specifically relates to Counts 1, 6 and 11 – all charges which carry the potential for a death penalty sentence. Those counts also ask jurors to determine whether, if not for the conspiracy, race spectators Krystle Campbell, Lingzi Lu and Martin Richard, as well as MIT Police Officer Sean Collier, would not have been murdered.

Collie was allegedly executed by the Tsarnaev brothers three days after the bombings, April 18, 2013, as the FBI was hunting them down.

Second, the jury asked O'Toole what the difference is between aiding and abetting. The verdict form says "aiding and abetting" and "aided or abetted" throughout.

The question is a critical one for Tsarnaev, whose defense and hopes of getting a life sentence hinge on the jury believing he was doing his brother's bidding rather than being a ringleader.

O'Toole told the jury there is no difference between the words, which he defined as intentionally helping another commit a crime.

He said the phrase is a "singular concept" — in other words, terms that must be considered together, even though the verdict form sometimes reads "or," and sometimes "and."