How can you listen to a police scanner for free that you control?

You can listen to a police scanner for free by using online services or apps that stream police radio frequencies, such as Broadcastify or Scanner Radio. Additionally, you can set up your own scanner by purchasing a handheld or base model scanner radio, which allows you to control the frequencies you want to listen to. Many modern scanners also support programming via computer software, making it easy to customize your listening experience. Just ensure you are aware of local laws regarding scanner use.