S VISA ("Snitch Visa")

An alien who is in possession of critical reliable information concerning a criminal organization or enterprise;  is willing to supply or has supplied such information to Federal or State court; and whose presence in the United States is essential to the success of an authorized criminal investigation or the successful prosecution of an individual involved in the criminal organization or enterprise is eligible for an S VISA.   In general, these visas are made available through the interaction of the government agency that will benefit from the alienís presence in the U.S.  

This visa is also available to those eligible for a reward who have critical reliable information concerning a terrorist organization, enterprise, or operation which he or she will provide placing the alien danger. 

The spouse and unmarried children of the alien can get derivative status, is qualified.

T VISA (Victim of "Trafficking" Visa)

A T Visa is available to an alien who has been a victim of a severe form of trafficking in persons, is physically present in the United States, American Samoa, or the Commonwealth of the Northern Mariana Islands, or at a port of entry thereto, on account of such trafficking, is under 18 years old, assists in the investigation of trafficking, and would suffer extreme hardship involving unusual and severe harm upon removal.

U VISA (Abused victim of criminal act Visa)

The U Visa is a new category for aliens who have suffered substantial physical or mental abuse as a result of having been a victim of criminal activity such as organized crime or terrorist group. The alien must posses information concerning criminal activity and be willing to assist government officials in the investigation of the criminal activity.

If it necessary to avoid extreme hardship to the spouse, the child, or, in the case of an alien child, the parent of the alien would suffer because of that investigation or prosecution, derivative status may be granted.