How much force can be used by an officer when executing an arrest? How is it determined?

Explain at what point a person is considered “Under Arrest”. Explain the difference between a stop and an arrest. Why might states authorize probable cause for certain witnessed misdemeanors? How much force can be used by an officer when executing an arrest? How is it determined determined? Can you think of any times when you heard about “excessive use of force” and if so, how do you think the actions of a few influenced the perceptions of many regarding the police?