By criminal record she clearly mean the sort of things that would prevent you from being accepted to the bar/law school. Someone with a rape conviction as an adult wouldn't be sitting in a first year law lecture. Is is normal for law schools not to accept candidates that will not be able to become lawyers.

Certain criminal convictions (like rape) prevent you from being accepted by the bar. Most people don't go to law school when they know they are ineligible to actually practice law (even if a law school actually accepted a convicted rapist).

The school they were teaching at probably disqualified anyone with any criminal record from admission.