LAS VEGAS (KLAS) — A Las Vegas high school teacher accused of having sex with a student went to the girl’s home, talked with her on social media and changed a quiz grade from an F to an A, according to court documents.

Lawrence Artl, 37, faces one count of an employee engaging in a sexual relationship with a student over the age of 16 and two counts of preventing or dissuading a person from testifying.

Artl, a biology teacher at the Las Vegas Academy of the Arts, turned himself into police last week.

According to Clark County School District police, the investigation started in February 2020. He has been a teacher since 2007.

The student told police Artl went to her house twice, court documents stated. During the second visit, she and Artl had sex. On other occasions, the student kissed Artl in his car.

Investigators said Artl and the student first communicated via school email, but switched to Snapchat, a social media platform where pictures disappear after they are viewed.

After the investigation began, Artl told the student to block him on Snapchat and “delete everything,” investigators write in court documents. Around the time the investigation began, the student received a 4 out of 8 on a quiz, but Artl changed the grade to an 8 out of 8, investigators said.

Last week, a judge ordered Artl to stay away from young people he is not related to. He is due in court in September.

The sexual relationship charge is a felony and carries a sentence of prison time and a fine.