Police Powers Are Not Uniform
Every state treats its police forces differently. While usually granted broad powers and protections, there are exceptions. Not knowing the differences from place to place can lead to severe consequences
While courts have ruled that recording the police in public is protected under the 1st Amendment, other rulings contradict this. Additionally, these rulings only apply in public places rather than in private encounters.
This is a very delicate issue - knowing what each state's laws say on the matter is important and can keep you out of jail.
Only about one-in-five states require you to obtain the consent of another before recording a conversation with them, including the police. Knowing whether you are in a one-party or two-party consent state can save you felony charges.
Personal Information Disclosures
If a police officer has probable cause that you have committed a crime you must usually provide them your personal information, but what if they don't have probable cause?
If stopped on the street, at a checkpoint, or anywhere public what you must tell an approaching officer varies significantly. Over half of states don't require you to tell police anything at all. While some require you to disclose your name, address, birthday and/or what you are doing its important to know on the spot whether an officer's request counts as a personal question or if it carries the force of law.
Most states allow searches and frisks for weapons by police officers. What happens if they find something? As usual, it depends on the state.
If you are carrying a weapon in a state that requires you to disclose that to an approaching police officer immediately and you fail to do so, that can mean a serious charges. In some places its not a big deal if an officer finds a concealed weapon. They'll hold on to it and give it back at the end of the encounter. In others it can mean a hefty fine and a permanent loss of that and any other weapons.