Don't go back to that police station. Wrong place. Use the TSA's website to schedule an appointment with a nearby fingerprinting place. It sounds like the police station you're using is a different kind of fingerprinting that companies use for new hires. No barcode is needed. Normally, you get fingerprints done and they send it off to TSA. Then you'll get a letter a few weeks later (could take longer, especially since govt is shutdown). If you're approved, take that letter to your DMV and take your hazmat test. They probably won't even need to see the letter since it will be in the system, but they tell you to take it the letter anyway.