In this position you may be working with individuals who are underage and/or vulnerable. We do full background checks on all of our employees. Are you willing to comply?
This is where you must disclose to the interviewer if you do not have a clean criminal background. Discuss with the interviewer your willingness to comply and be sure to disclose any pain points ahead of time. It is better they find any marks on your record directly from you!
"Yes, I am happy to comply with any criminal, financial, and educational related background checks that you require. I had to undergo a background check recently for my position at my school. You will find that my record is clean."
