BOSTON - Lawyers for Boston Marathon bomber Dzhokhar Tsarnaev rested their case in his federal death-penalty trial Tuesday, a day after they began presenting testimony designed to show his late older brother was the mastermind of the 2013 terror attack.

The defense admitted during opening statements that Tsarnaev participated in the bombings. But Tsarnaev's lawyer said he was a troubled 19-year-old who had fallen under the influence of his radicalized 26-year-old brother, Tamerlan, who died following a shootout with police days after the bombings.

Prosecutors and Tsarnaev's lawyers will give closing arguments Monday. The jury is expected to begin deliberations the same day.

The defense has made it clear that its strategy is not to win an acquittal for Tsarnaev, now 21, but to save him from the death penalty. Three people were killed and more than 260 were injured when two pressure-cooker bombs exploded near the finish line April 15, 2013.

If the jury convicts Tsarnaev - which seems a foregone conclusion because of his lawyer's admission - the same jury will be asked to decide whether he should be executed or spend the rest of his life in prison.

During its brief case, the defense called four witnesses, including a cell site analyst who showed that Tsarnaev was at the University of Massachusetts-Dartmouth when Tamerlan purchased components of the two bombs used in the attack, including pressure cookers and BBs.

On Tuesday, an FBI fingerprint examiner testified that Dzhokhar's fingerprints weren't found on any of the bomb components, but Tamerlan's were. Elaina Graff said Tamerlan's prints were detected on two pieces of cardboard that came from one of the bombs used at the marathon and on a piece of paper found inside a backpack used to carry a bomb.