Runyon v. United States

Issue: (1) Whether, in order to demonstrate that evidentiary errors in a capital sentencing proceeding were harmless, the government must establish that the errors did not affect the verdict of the jury that actually heard the case or whether the government may instead meet its burden by demonstrating that such errors would not have affected a hypothetical, reasonable jury; and (2) whether, under the cumulative error doctrine, a reviewing court must reverse if the government cannot establish that preserved errors are harmless beyond a reasonable doubt, or is reversal required only if the errors “so fatally infect[ed] the trial that they violated the trial’s fundamental fairness.”