ST. JOHNS COUNTY, Fla. -

A now-former St. Johns County substitute teacher is out on bond after being arrested on charges of having sex with a teenager.

Stacey Slamka, 49, was arrested March 20. She is charged with three counts of unlawful sexual activity with a minor.

Investigators say that between December 2011 and January 2012, she had sex with a 16-year-old boy six times.

Deputies say the two met, then started communicating over the phone and on Facebook. They say she picked him up and took him to Hastings, where they had sex.

School officials say they started investigating Slamka in March 2012 for sending inappropriate text messages to a student, and she was then fired.

She was a substitute teacher at Gamble Rogers Middle School, Pedro Menendez High School, St. Augustine High School, St. Johns Technical High School, Murray Middle School, and Gaines Alternative and Transition Schools.

Slamka had no prior disciplinary issues before the inappropriate texts to a student.