...one of your statements was wildly inaccurate:

"The idea that a fact should be ruled irrelevant in the trial phase, then all of a sudden become critical in the sentencing phase, is inane."

If you have ever been on a jury where you had to determine both verdict and penalty you would know this. The judge's guidelines cover both aspects of your decision making process. Laws that pertain to determination of guilt or innocence are different from the laws and guidelines that you apply to determine the penalty. However, the plaintiff must present the information to support both decisions.

At least that's how it was in the trial I was on. During the trial the plaintiff mainly presented information to support the claim of wrongful death. But they also presented information that established the worth of the life that came to an end. And information about the cost, financial and emotional, to the family of the deceased. This information had nothing to do with the guilt or innocense of the defendents. And this information was referred to in the judges instructions to the jury.

The jury got to paw through family pix and arts and crafts done by the deceased saved by his mom from when he was a kid. Personal letters. Income information, Etc.