Stephen Silva was convicted of giving a firearm to Boston Marathon bomber Dzhokhar Tsarnaev.
Tsarnaev’s legal team said the convicted bomber doesn’t deserve the death sentence.
Other infamous convicts, including the "Shoe Bomber," also are housed at the Colorado prison.
The move was expected from his legal team following his conviction and sentencing earlier this year.
Two dozen victims and survivors addressed Dzhokhar Tsarnaev earlier on Wednesday.
Khairullozhon Matanov was sentenced for obstructing the Boston Marathon bombing investigation.
The jury deliberated for almost 15 hours; defense lawyers were expected to quickly appeal the death sentence.
Assistant U.S. Attorney said the ethnic Chechen had turned against his adopted country.
Here's what we know about the Boston Marathon bomber from the two phases of his trial.
Boston Marathon bomber Dzhokhar Tsarnaev told a Roman Catholic nun and prominent death-penalty opponent that "no one deserves to suffer" as the victims of the deadly 2013 attacks had.
Dzhokhar Tsarnaev apologized after he raised his middle finger to a cell surveillance camera following his arrest in 2013, a witness said.
Katherine’s mother, Judith Russell, testified that she didn't want her daughter to be with Tamerlan Tsarnaev.
Once a heavy drinker, a Boston Bomber transformed into someone obsessed with Islam.
The defense argued Dzhokhar Tsarnaev fell under the sway of his older brother.
A new book examines what shaped the men who launched the Boston Marathon attack.
Watertown Police patrolman John Reynolds recalled chasing the brothers in two cars.
Tsarnaev, 21, is charged with killing three people and injuring 264 with a pair of homemade bombs.
Attorneys for Dzhokhar Tsarnaev argue an impartial jury could not be seated so close to the site of the attack.
The field of potential jurors called for the case is the largest ever summoned to Boston federal court.
The accused, Dzhokhar Tsarnaev, could face the death penalty if found guilty of the April 2013 Boston attack
As Dzhokhar Tsarnaev awaits trial for his alleged role in the Boston Marathon bombing, many of the women in his life are still proclaiming his innocence—and pushing for jihad
Tsarnaeva reportedly called and threatened her boyfriend's ex-girlfriend