How do you program radio shack pro 651 police scanner?

Each Scanner is different. Check your manual for more information on the exact process that will get you set up correctly. Most manuals are available online as a PDF download. They may also offer to mail you a hard copy manual for a cost. Frequencies change over time, so it's a good idea to check every year or so for new or updated frequencies in your area. A general FAQ and USA scanner frequency database is provided below.