The defense wants to call the notorious Sister Helen Prejean to testify in the trial of the Boston Marathon Bomber. I can't fathom that she can offer any relevant evidence.
"Evidence is relevant if: (a) it has any tendency to make a fact more or less probable
than it would be without the evidence; and (b) the fact is of consequence in determining the action." Federal Rule of Evidence 401. "Irrelevant evidence is not admissible." FRE 402.
What are the facts of consequence in the penalty phase of a federal capital cases? They are the mitigating and aggravating factors listed in subdivisions (a) and (c), respectively, of 18 U.S.C. §3592
. Obviously the defense does not want to introduce evidence in aggravation, so that leaves the mitigating factors in subdivision (a).
The relevant mitigating factors are impaired capacity, duress, minor participation, equally culpable defendants getting off with less, no prior criminal record, mental disturbance, victim's consent, and the catchall factor: "Other factors in the defendant's background, record, or character
or any other circumstance of the offense
that mitigate against imposition of the death sentence."
Any evidence that is not about this crime
or this defendant
and therefore inadmissible.
What does Helen Prejean know that is relevant? Nothing, I strongly suspect. If not, she should not testify.