Special hearing to determine whether a sentence of death is justified

If, in a case involving an offense described in section 3591, the attorney for the government believes that the circumstances of the offense are such that a sentence of death is justified under this chapter, the attorney shall, a reasonable time before the trial or before acceptance by the court of a plea of guilty, sign and file with the court, and serve on the defendant, a notice— If the attorney for the government has filed a notice as required under subsection (a) and the defendant is found guilty of or pleads guilty to an offense described in section 3591, the judge who presided at the trial or before whom the guilty plea was entered, or another judge if that judge is unavailable, shall conduct a separate sentencing hearing to determine the punishment to be imposed. The hearing shall be conducted— before a jury impaneled for the purpose of the hearing if— If, in the case of—