There is a general rule in misdemeanors that the police officer must observe the violation before making an arrest. However, there are dozens of exceptions to this. Can an anonymous 911 call suffice for an arrest for DUI? Obviously, if it can, there is a great deal of opportunity for spiteful mischief, i.e. an angry ex-spouse calling in a DUI on the other ex-spouse. Read the following article to find out more about this issue, as it is permitted, but with certain limits.