Dzhokhar Tsarnaev's lawyers will appear in federal court in Boston Thursday to appeal his death sentence for his role in the 2013 Boston Marathon bombings. WGBH News Legal Analyst and Northeastern Law Professor Daniel Medwed joined Morning Edition Host Joe Mathieu to discuss the claims being raised by Tsarnaev's defense team. The transcript below has been edited for clarity.

Joe Mathieu: So, first of all, what should we expect Thursday in terms of format? What will this proceeding actually look like?

Daniel Medwed: Well, an appellate argument does not resemble a trial. There won't be any witnesses, no new evidence, no jury. The defendant typically isn't in the room. It's a formal legal argument before some judges. And the attorneys are confined to issues that were presented to the trial judge. So the defense is going to claim that certain errors occurred at trial that would justify a new trial or maybe a reduction of the sentence to life in prison. The prosecution obviously will push for the status quo.

Now, the parties have already submitted voluminous written briefs to the First Circuit Court of Appeals. That's the court with jurisdiction here. The defense brief, get this, clocked in at more than 500 pages. And Thursday is just a chance to argue orally in front of those judges — for an hour apiece — to expand upon those arguments. Now, the most important takeaway here, appellate cases are won or lost based on the briefs, not the oral argument. The oral argument is a chance for judges to ask questions. And therefore, it's important for us to pay attention to those questions, to gain insight into where the judges are leaning.

Mathieu: So let's look at Tsarnaev's main legal arguments, Daniel. Among other things, the defense is arguing that the trial should not have happened here. It should not have taken place in Boston. How strong is that?

Medwed: It's a fairly strong claim. So essentially what happened before, is that the defense team filed what's called a change of venue motion, asking the judge to transfer the case somewhere else in the first circuit, maybe Springfield or Providence — somewhere else. And the judge turned it down. Now, for purposes of full disclosure, I did sign an amicus brief — a friend of the court brief — siding with the defense position here. But the arguments basically go like this: On the one hand, there's a principle, a presumption that the community that's aggrieved by a crime should have a say in the outcome. The people of Boston were hurt by the marathon bombing. We should have a say in the trial. But on the other hand, if the crime is very notorious and gets intense publicity throughout the process, then there's a risk that the jury is tainted. It will be unable for the judge to find a fair and impartial jury. And given the unabated coverage of the Boston Marathon bombing from April 2013 to the run up to trial, I think there's a fairly good argument that it was hard, if not impossible, to get a fair trial here.

Mathieu: What else catches your eye from the defense that could be compelling to the judges?

Medwed: Well, another issue, and there are lots of issues here that I found compelling, relates to how the trial judge limited or curtailed the defense from developing the argument that Tamerlan Tsarnaev, Dzhokhar's older brother, was controlling, abusive and manipulated his younger brother into this, to the point that his younger brother should have his life spared. Specifically, the defense was limited in its ability to introduce evidence about Tamerlan's potential alleged involvement in a gruesome triple murder in Waltham back in 2011. The reason why this might be compelling is not that the evidence of Tamerlan's involvement is especially compelling, but just that judges are often quite lenient in letting defendants develop what's called a mitigation argument — an argument that suggests that, yes, the person did it, but maybe the person's life should be spared because of extenuating circumstances.

Mathieu: Do you think Tsarnaev has a shot at winning the appeal?

Medwed: Well, here's my breakdown of it. After a conviction, the presumption of innocence vanishes, a presumption of guilt takes over, and the burden shifts from the prosecution to prove guilt beyond a reasonable doubt to the defense to show that these errors that occurred justify a reversal. So it's hard, in theory, to win on appeal. That said, in death penalty cases, judges often scrutinize the cases very carefully, because as a friend of mine once wrote, "There's no appeal from the grave." It's the ultimate punishment. So when you look back at federal death sentences — and there have been more than 80 of them in the last three decades — only three of those sentences have actually resulted in execution. Some of those cases are still pending, others were converted to life sentences. So I think it's it's a non-negligible chance of some relief. That doesn't mean Tsarnaev is ever going to breathe free air. It just means that perhaps eventually it could be reduced to a life sentence.