The firing came five weeks after John O'Mard was arrested for allegedly having sex with that 16-year-old boy who graduated from the The J.W. Dodd Middle School, where he worked.
School board officials say they've learned O'Mard already had a criminal record that he hid by submitting fake fingerprints during a background check in 2003.
O'Mard, who served almost year in jail after a 1990 conviction for grand larceny and a 1987 petty larceny conviction, faces up to 4 years in prison if convicted on the new charges.
Police say O'Mard met the 16-year-old boy online in September.