What type of crime is interfering with a police officer?

Any act that prevents or impedes an officer from performing his official duties can be characterized as interfering with a police officer. This can range from knowingly providing false information to an officer (especially if it is in reference to your identity or age), to purposely slowing his response to a crime scene or an investigation, to shouting insults or trying to draw a crowd when an officer is questioning or arresting someone. The latter is a special cause for concern, as as officer can find himself outnumbered and at personal risk for executing his duties.

Police officers have no obligation to explain what they are doing or why they are doing it at the scene of an arrest or investigation. Those explanations take place in the officer's report or in testimony delivered in court. If you believe the police are engaging in misconduct, you have a right to be a passive witness and to report what you see and hear, and anyone at trial can have you testify in their behalf, so long as your account is relevant to the charge(s). On the street, do not interfere with the police. You are inviting a battle you will almost certainly lose.