A veteran prosecutor who nailed the Pentagon leaker and convicted an ex-Harvard professor with ties to China has been put on the Boston Marathon bomber’s last-ditch death penalty appeal.

Assistant U.S. Attorney Jason Casey is “counsel for the United States” against Dzhokhar Tsarnaev, who has won his appeal to determine if he deserves a new death penalty trial.

Casey, from the Boston office, was just given the post, according to a one-page update to Tsarnaev’s voluminous federal file. Tsarnaev is attempting to escape the electric chair or, more likely, a lethal injection. He is now a prisoner in a Colorado super-max.

Casey recently won a guilty verdict from Massachusetts Air National Guard member Jack Teixeira, who must serve at least 11 years in jail. He also faces a military court-martial.

Casey is also named in the case against Dr. Charles Lieber, former chair of Harvard University’s Chemistry and Chemical Biology Department. Lieber was found guilty last year of lying to federal authorities about his links to China’s Wuhan University of Technology and failing to report income. He was sentenced to two days in prison and six months of home confinement.

Now Casey is up against the marathon bomber who has questioned the bias of two jurors in his 2015 death penalty trial.

The appeals court stated “the district court’s investigation fell short of what was constitutionally required” over this one issue. If bias is shown, the court adds, Tsarnaev will be “entitled to a new penalty-phase proceeding.”

The alleged bias is over social media postings about the bombing made by two jurors.

The appeals court has added “regardless of the outcome, (Tsarnaev) will spend the rest of his life in prison.”