With testimony finished in the trial of Boston marathon bomber Dzhokhar Tsarnaev, jurors now have to figure out how whether the portrait painted by his defense team can be reconciled with the impassive defendant they saw in court.

As they try to save their client's life, lawyers for Tsarnaev have offered a bevy of arguments. They've said Tsarnaev was a sweet kid, and a sweet teenager — at least, before the marathon bombings. And they've said his chaotic family life and Chechen cultural norms left him in thrall to his older brother Tamerlan, who was a frighteningly bad guy.

The defense has also argued that Dzhokhar Tsarnaev's brain was unformed when he became a terrorist. And on Monday, they suggested that he's actually remorseful — allegedly saying, of the marathon bombing victims, "No one deserves to suffer like they did."

It's a rich psychological portrait — but whether it provides any real insight into Tsarnaev himself is debatable. The defendant never took the stand. He was laconic throughout the trial, seemingly unmoved as victims and family members recounted the pain he and his deceased older brother caused. (One notable exception: he seemed to tear up when an aunt, flown in from Russia to testify on his behalf, grew extremely distressed on the witness stand.) On Monday, after the prosecution and defense rested, everyone in court turned to watch the jury file out — except Tsarnaev, who looked the other way and chatted with one of his attorneys.

After weeks of testimony, it's still hard to square the youth described by the defense, who allegedly made a harrowing and tragic descent into terrorism, with the unflappable young man we've seen in court. In an infamous tweet sent shortly after the bombings, Tsarnaev described himself as a "stress free kind of guy." That description still seems to fit. And it could end up being the reason that Tsarnaev's defense falls short.