These photos were examined by the Stuchman Forensic Laboratory in August, 2006, to determine if the man was the same in both photographs.  Confirmed.

First photo:  given by Nguyen Chi Thien to the British Embassy with his manuscript, Hoa Dia Nguc.on July 16, 1979.

Second photo:  taken in San Jose, California, at the home of his friend Thanh Tran by Jean Libby on March 5, 2005.