Isn't sentencing the judge's responsibility, and not the jury's?
I believe there are differences in the general rule when it comes to potential capital punishment.
Yeah, most states have penalty phases for juries only for death penalty and certain civil cases.
However, I don't think there's any guarantee in the constitution that a death penalty decision can't be rendered by a judge instead. I think this law is ridiculous and should be abolished, but if I was on a jury I'd be far more comfortable with a judge sentencing a killer to death against my wishes than with letting that killer go to prevent it.