Can an employer pay part of staff over time and pay others comp time for same shift

What you have described does not sound legal. Employees performing the same job functions should generally be compensated in the same manner. If you are working for a private employer, then comp time is not permitted. I would encourage you to contact an employment attorney to discuss this further. My office offers free consultations, we work on a contingency fee, and we regularly wage and hour issues.   Ohio wage and hour attorney www.mcoffmanlegal.com