If you do not want your emails to be sent to your BlackBerry, then go to the Email Settings/Setup Application on the BlackBerry and delete the email addresses.
Since you have not indicated where you live (or where you want to listen to the police scanner), we can only guess.
One place to start looking is BlackBerry App World. There are 407 applications returned when one searches for "police scanner". (Note that some of hits are just for 'scanner'.) None of the police scanner applications appear to be free. But most are low cost. You will need to look through and see if your area is covered. Search Results for "police scanner" - BlackBerry App World
And please, please try to use some capitalization and punctuation in your posts.