NREMT has a separate criminal conviction policy than the states and may also choose to deny certification for an applicant even if a state approves the student to certify in their state. That doesn’t typically occur, but it COULD, so be sure you are aware that you may need to question NREMT about your ability to certify if you have a criminal background but are accepted into this program. Here is a link to the NREMT policy:
https://www.nremt.org/rwd/public/document/policy-criminal