Houston immigration lawyer Trang Le Nguyen, who was charged Monday in a massive marriage fraud scheme, has pleaded not guilty, and was released on a $100,000 bond as her case proceeds through federal court.

Nguyen, managing partner in Pham & Nguyen Law Group in Houston, is one of 96 defendants facing 206 charges total in the case, in which the government alleged a large-scale conspiracy to create sham marriages between immigrants and U.S. citizens to circumvent immigration laws. For her alleged role in the scheme, Nguyen faces charges of obstructing and impeding the due administration of justice, tampering with a witness, mail fraud and conspiracy to commit mail fraud.