A former Booker T. Washington High School English teacher has entered a plea of no contest to charges of having sex with female students. State Attorney Bill Eddins said 31-year-old Mark Lua was charged with one count of promoting the sexual performance of a child and three counts of unlawful sexual activity with minors. Lua will be sentenced in December by Escambia County Circuit Court Judge Jeffrey Burns and faces a maximum of 20 years in prison and will be designated a sex offender for the rest of this life.