Nora Martinez, 30, Math teacher, Coke R. Stevenson Middle School, San Antonio TX

Nora Martinez resigned just before her arrest on allegations of an indecent relationship with a middle school student. The parents of a 13 year old student intercepted text messages the teacher had sent.

Melissa Petro, 30, Art teacher, Public School 70, Bronx NY

Melissa Petro, was reassigned after her school discovered she was a former prostitute. According to the New York Post, the tattooed sex worker taught art at Bronx elementary school PS 70 for three years and managed to keep her past life a secret from parents and faculty.

Well it happened before she was a teacher. Does that matter?

Bronx Teacher Admits To Selling Sex on Craigslist

Update Dec 27 2011:  She has posed nude for Penthouse.