SALT LAKE CITY (AP) – A former Utah high-school teacher who pleaded guilty to having sexual relations with three of her students faces up to 15 years in prison when she is sentenced Thursday.

One of the boys was 16 and two were 17 when Brianne Altice had sex with them, and she continued one of the sexual relationships after she was first arrested two years ago, prosecutors say.

Altice, 36, cried as she pleaded guilty to three counts of forcible sexual abuse in April in return for prosecutors dropping 11 other charges.

She sent a handwritten letter to Judge Thomas Kay asking him to impose a more lenient sentence, saying she is harmless and promising the crimes would not happen again.

Prosecutors say she befriended the boys, allowing them to hang out in her classroom, and the relationships later turned sexual.

One victim testified that the relationship began with kissing between class periods and eventually led to intercourse. Another said he considered her to be his girlfriend during their yearlong sexual relationship.

Defense attorney Ed Brass defended her by saying she was no longer the boys’ teacher when the sex occurred. He later said she agreed to the plea deal because she wasn’t sure what might happen at trial.

Altice was first arrested in October 2013 after a student reported having a relationship with her. The two other victims later came forward with similar allegations. She was out on bail until allegations emerged earlier this year that she had sex with one of the victims after her arrest. A judge then ordered her to jail.

Parents of two of the boys sued the school district, saying officials knew Altice was behaving inappropriately but didn’t do enough to stop her. They said the running joke at the high school was, “Who is Ms. Altice sleeping with now?”

One lawsuit has since been withdrawn after state attorneys contended in court papers that schools aren’t responsible for injuries arising from assaults. Another is still pending.

Altice was hired by the Davis County School District in 2004 and had been teaching English at the high school since August 2012. She was fired shortly after the allegations came to light, and her husband also filed for divorce and custody of their child.