It will not act as a police scanner, in stock form. Police/fire/emergency operate on specific channels/band of the radio frequency spectrum.
CB-citizens band radio= public use only. But you can usually (check your model) change the receiver crystal to pick up any channel you want, including police. And air traffic etc.
But be careful. You have a receiver/transmitter not just a scanner. They don't know you are scanning unless they actually see you with the radio and test it. But if you start broadcasting on secure channels,well they take that very seriously. It is possible to track your repeated transmissions and bust you hard. Do not do anything like a joke mayday as that is big fines and likely jail. And if there are real consequences, like they roll out air rescue for your joke, you will go down for a few years. The FAA does not give friendly warnings.
Check local laws. Some places do not like you to have even a scanner.
And for sure your transmitter chipped for secure channels will be illegal.
But the degree of illegality and punishment varies from place to place.
I'm sure you can buy fancy digital radios that can scan the full spectrum, so you never have to rechip.
Sometimes just having police crystals is illegal.
I know you were not even thinking of making illegal broadcasts, I'm just saying. Because the police have no sense of humor on this.