In Massachusetts there is a General Law, Chapter 90, Section 10 saying that you need to have a license in Massachusetts and that is where you look up the standard, but what the court has to be able to prove, is that the person actually operated a motor vehicle, did so in a way and without having a valid license to operate.  The way though does not mean public way and the way is more inclusive then somebody who is operating under the influence of alcohol.  The person does not need to have knowledge that he/she lacked a valid license, but it is one of the more minor criminal offenses and there does need to be documentation that has to be introduced to prove the charge.  The mere fact that a person does not have his/her license on them is not enough to prove his/her unlicensed status.

Generally, they need to get a certificate from the Registry; which is not easy to obtain, and a lot of times because of it being such a minor offense, the prosecution might not go to the effort.