S visa is divided in two category: 1. S-1: It is issued to a person who is in possession of critical reliable information concerning a criminal organization or enterprise who is willing to supply or has supplied such information to federal or state law enforcement authorities or court and whose presence in the U.S. the Attorney General (AG) determines is essential to the success of an authorized criminal investigation or prosecution. 2. S-2: It is issued to an individual who both the Secretary of State and AG jointly determine that 1) he/she is in possession of critical reliable inforamtion concerning a terrorist organization, enterprise or operation; 2) is willing to supply such information to federal law enforcements or federal court; 3) will be or has been placed in danger as a result of providing such information; and 4) eligible to receive an award under 22 U.S.C. §2708(a). 200 visas for S-1 and 50 for S-2 are available per year. Maximum stay is for 3 years. No extension and change of status is permitted
U.S. Immigration Law
