It's FIRST, not USFIRST, as shown
here (FIRST's own material),
Here, FIRST's official FAQ sheet , and
here - in Dean's FIRST bio
This is a good discussion. I agree that a team should be protective and take a solid stance to put student's safety ahead of the rights of a convicted criminal. Difficult choices may need to be made, and they should fall on the side to protect the students.
From what I hear, FIRST will be requiring some sort of mentor screening in the upcoming year. I am not sure how they are planning on doing it, but notice
Here that they have already started this in FIRST LEGO League.
Andy B.