A former physical education teacher was given a jail term yesterday because she continued to communicate with a ninth-grade boy after police charged her with having sexual relations and transmitting nude photos of herself to him.

Beth Ann Chester, 27, formerly of Moon Area Senior High School, pleaded guilty yesterday in Allegheny County Common Pleas Court.

Deputy District Attorney Laura Ditka said the now 15-year-old boy's family would have been willing not to prosecute had she ceased contact with him. Instead, they struck up a brief exchange after she was released on bond and a judge put her on house arrest.

Ms. Chester, of Scott, who initially faced 11 criminal charges, pleaded guilty before Judge David R. Cashman to reduced charges of statutory sexual assault, criminal use of a communication facility -- a cell phone -- and corruption of a minor.

He sentenced her to 1¹/₂ to three years in Allegheny County Jail, followed by five years' probation during which she may not have cell phone access. He ordered her to continue mental health counseling and prohibited her from further contact with the student.

"I just want to apologize to everyone involved in this situation. I know this is a punishment I deserve and I'm very sorry for it," Ms. Chester said before a sheriff's deputy placed her in handcuffs and led her from the courtroom.

The prosecutor told Judge Cashman that Ms. Chester relinquished her license and "she will never teach again in the state of Pennsylvania."

She resigned for undisclosed "personal reasons" on Dec. 27. Moon police got involved a week later after she confided in a fellow physical education teacher -- who told administrators -- that she'd resigned after a 14-year-old student's parents became aware of text messages she'd exchanged with the boy.

At a meeting at a Starbucks in Robinson Town Centre, the boy's parents had asked her to resign and to leave the child alone.

The boy later told police he was in love with her. They found lewd text messages from Ms. Chester and nude photos of her on his cell phone. The boy also told authorities they had intercourse.

Attorney Robert G. Del Greco Jr. said his client, who is separated and in divorce proceedings, mistakenly "looked at this group of students as her peer group."