Boston Marathon bomber Dzhokhar Tsarnaev has the outside world “piped into his cell” through a TV offering 50 channels of TV programming while awaiting execution at a prison dubbed the “Alcatraz of the Rockies,” according to newly unsealed court documents.

As the December deadline for producing his first appeal looms, dozens of motions, transcripts and exhibits barred from public view for more than three years are shedding light on the behind-the-scenes story of Tsarnaev’s 2015 trial — including his willingness to plead guilty if guaranteed his life would be spared.

In the days leading up to a federal jury’s verdicts that Tsarnaev be put to death for terrorism and murder, incensed prosecutors were fighting behind closed doors to show jurors that life in solitary confinement at the Supermax penitentiary was not crueler than lethal injection.

Describing the facility in Florence, Colo., in the most austere terms, Tsarnaev defender David Bruck had assured the panel his client’s view of the world would be limited to a sliver of windowpane exposing only the sky above a hellacious and barren landscape.

Later, Assistant U.S. Attorney William Weinreb protested to U.S. District Court Judge George A. O’Toole Jr. during a private lobby conference, “He will not be blocked from view of the outside world because it will be piped into his cell through a screen.”

Prosecutor Steven Mellin chimed in, “There are 50 channels of DirecTV that’s piped into their room along with music as well, so the inmate controls all of that. They can watch whatever television stations they want. They can watch educational training, they can watch videos that are … to workouts like yoga or something.”

Ultimately, O’Toole allowed John Oliver, the USP Florence complex warden, to testify that inmates watch “prison programming.” The judge warned Mellin to stop there.

Tsarnaev’s trial for the deadly Patriots Day 2013 bombings in Copley Square and the murder of MIT Police Officer Sean Collier began on Jan. 5, 2015, with jury selection and ended more than six months later with his formal sentencing.

As early as October 2013 – and even as the trial progressed – Tsarnaev, now 25, repeatedly offered to plead out, acknowledging in a letter to prosecutors, “Killing and hurting innocent people is wrong,” documents state.

Weinreb told O’Toole during an April 13, 2015, closed motion hearing that what Tsarnaev refused to do was “help the government” by answering questions about additional threats and “many, many, many things the government very badly wanted to know.”