Answer: There are three different levels of police encounters. There’s what’s called a level one consensual encounter where an officer can come up and pull someone aside just to talk to them and they don’t need any sort of suspicion.
Level two is where the officer needs to have reasonable articulable suspicion that you are committing a crime or that a crime has been committed. If they believe that a crime has been committed or that you are about to be engaged in criminal activity, they’ll ask to put their blue lights on and stop you and seize you.
In the event that they believe that a crime has been committed they have what’s called probable cause, meaning that more likely than not that a crime has been committed. If they can establish that, then they’re allowed to go ahead and place you under arrest. So there’s the three different levels of encounters that you can have with the police. But first, in order to stop you, they generally need reasonable and articulable suspicion of a crime that’s been committed or is in the process of taking place. Probable cause means that they believe that a crime has taken place and they have enough evidence to go ahead and arrest you.
And then there’s guilty at a reasonable doubt, which is that in order to convict you of a crime, they have to establish not that you may have done it or probably committed the crime, but that you have committed the crime beyond a reasonable doubt.