Many people are under the mistaken impression that just because a crime is labeled a Misdemeanor or a Traffic Violation that the event will not have an effect on their Green Card. This is just not the case because a Green Card holder can lose their green card if they have done certain acts. Immigration rights are controlled by U.S. Federal Law which decides which crimes are serious or not regardless of the fact that a State may call their law a minor offense (misdemeanor). The Green Card Holder does not even have to be convicted of the crime just being arrested or admitting to the illegal act may affect their right to keep their Green Card.
Crimes to be particularly careful about are any crimes with drugs involved, violence involved, stealing (theft) involved, deceit (fraud), domestic violence involved or traffic accidents resulting in physical injury or extensive damage to property. There are many other types of crimes but these are some of the more common ones that end up having Green Card Holders put in Deportation (Removed from the U.S.) Proceedings.
In some cases, the person may not know that their Green Card can be taken away. They usually only find this out when they are returning from a trip outside the U.S. (Where CBP will run a criminal background check on them) or when they apply for Citizenship (instead of getting U.S. Citizenship they get a Deportation Court Notice).
There are many situations that can be fixed but a Green Card Holder must act immediately. Any Person having a green card who has been arrested, detained, convicted or even involved a traffic accident should get a copy of all the court documents, police reports/accidents and any other related documents. They should see an Immigration Attorney as soon as possible to find out if this will affect their Green Card, if it can be fixed and how best to fix it.
Please contact a licensed Immigration attorney before you act on your specific situation. Immigration Laws and Federal Regulations are constantly changing and the general information provided can change over time.