COEUR d’ALENE — A Lake City High School teacher is accused of having a sexual relationship with a former student.

William J. Keylon, 48, of Hayden, is charged with lewd conduct with a minor under the age of 16, a felony punishable by up to life in prison.

Keylon turned himself in late Wednesday after a judge issued a $100,000 warrant for his arrest.

The inappropriate relationship allegedly began in 2012 and lasted for several years while the student attended Lake City High School.

Coeur d’Alene police said they learned of the relationship in July and worked closely with the Coeur d’Alene School District to investigate. Police interviewed the former student and others before obtaining an arrest warrant.

The district has placed Keylon on administrative leave pending the outcome of legal proceedings. He has been a teacher at Lake City since 2003. Last year, he taught a web design/development course and a computer science/programming course.

The former student, who is now an adult, told police that Keylon engaged in sexual activity with her on multiple occasions when she was between the ages of 15 and 18.

She told investigators Keylon first began paying attention to her during her freshman year, when she was facing difficulties in her home life, and made her feel as though he cared about her.

He was “flirtatious” with her and allowed her to hang out in his classroom while she should’ve been in other classes, she told police. They allegedly communicated outside of school via email and Snapchat.

She reportedly said she didn’t want to engage in sexual activity with Keylon but felt obligated to do so when they were alone together.

The former student also told police she and Keylon exchanged nude photos while she was underage.

A different former student reportedly told police that, when she was 15, Keylon gave her money, invited her to his house on multiple occasions and once slapped her rear.

Police obtained a copy of an email that corroborated some of the details she described, according to court documents.

An investigation is ongoing, police said, and detectives believe Keylon may have committed additional crimes.

Police encourage anyone with information related to any inappropriate behavior involving Keylon to contact the Coeur d’Alene Police Department.