William C. Friskey, a former English teacher at Ledyard High School, went to prison this morning for having an illegal sexual relationship with a student.

The 36-year-old East Lyme resident will serve at least nine months, the mandatory minimum, of his two year sentence for second-degree assault. He had pleaded guilty in December.

“This is a violation of trust on so many levels,” Judge Hillary B. Strackbein told Friskey. “On your family, your students. There’s no way parents send their children to school and expect something like this to happen.”

The victim, who was 17 when Friskey initiated the sexual relationship in 2013, did not attend the sentencing, though there were family members in court on her behalf. Friskey will be on probation for 15 years following his release and will be required to register as a sex offender for 10 years.

Friskey had worked for the school district since 2007. He resigned two days after he was arrested by town police.

“He was a very respected teacher, well-liked by staff as well as students,” said his attorney, Peter D. Catania. “He could not be more remorseful for what happened.”

Since his arrest in July 2014, Friskey has accepted responsibility and engaged in counseling and treatment for a mental health issue, according to Catania.

Prosecutor Theresa Anne Ferryman said the victim’s family expressed how damaging the incident had been during a presentencing investigation.

“The defendant abused his professional position,” Ferryman said. “He emotionally manipulated the victim for a period of time well after she expressed her wish to end the relationship.”

Friskey, who had come to court with a woman and was dressed in khaki pants and a large green sweater, did not address the court before he was taken into custody. Ferryman said he had made what appears to be a heartfelt statement of remorse during the presentencing investigation.

“It seems he does understand, intellectually, what he did,” Ferryman said.

According to an arrest warrant affidavit, Superintendent Cathy Patterson called town police on June 10, 2014 to report that a possible inappropriate relationship between a teacher at Ledyard High School and a female student had been brought to the attention of administrators.

Though the alleged victim was old enough to consent to a sexual relationship, it is illegal for school employees to have a sexual relationship with students. In an interview with police, the alleged victim said she and Friskey became friendly when she took his English class and began emailing each other after school hours. She said their conversations became more personal and in September 2013 she began visiting his classroom, where they would be alone with the door closed, during lunch and after school. She said she began visiting him at his home in during the second semester. She said she went to his house about 10 times, telling her mother she was going to a friend’s house, and that they went bowling together and to breakfast and dinner.

Friskey is married with children, according to testimony in court.

The teen told the investigator she tried to end the relationship several times because she knew it was wrong but that Friskey would “always try to pull her back in by threatening to harm himself or telling her he couldn’t live without her.” She said she finally ended the relationship last spring and that Friskey gave her a letter apologizing for allowing the relationship to become sexual and saying he regretted sacrificing their friendship.

Administrators provided the police with letters and emails and Skype chat logs recovered from a laptop that had been assigned to Friskey. In one letter, Friskey wrote that he could not “stand the thought” of the teen seeing him as her “abuser or even rapist.”

k.florin@theday.com

Twitter: @KFLORIN