I don't know if any state that has mandatory reporting of all crimes based solely on knowledge. Outside of mandatory reporting of child abuse for certain indiv

I don't know if any state that has mandatory reporting of all crimes based solely on knowledge. Outside of mandatory reporting of child abuse for certain individuals in specific roles (i.e. doctors, teachers, etc) so that those people report despite confidentiality obligations. But for the average joe walking down the street and witnessing a crime there is usually no obligation to report that and they don't magically become accomplice. Most state laws in the U.S. don't impose duties like that (or even duties to help others) on its citizens. Now, if your property is being used to commit a crime and you don't report it there might be different implications. And if you don't report it then you are going to have a difficult time proving you were involved. Guilt by association type scenario and the jury is going to likely believe you were involved. But this is not the same as becoming an accomplice because you didn't report the crime.