I suspect you don’t know many people who have gone to such schools.
There are young people with arrests and convictions who go to these schools. It all depends upon the circumstances.I think it’s rare, but it happens. In one well known case, Brown admitted someone who spent 8 years in prison. After he got out, he applied to Brown and was rejected. He then got a job and went to a CC where he racked up perfect grades. He then was accepted to Brown as a transfer student. After Brown, he went on to Yale Law School. His was an unusual story.
UChicago isn’t an Ivy, but I know a student with a juvenile conviction it accepted. He too is now a lawyer.
I know of a student whose father was involved in a major securities fraud case–a white collar case which was front page news–who went to Yale.
It’s all about the money. Your ex’s background doesn’t matter in the least.