Editor's note: This article contains graphic content.

A former Denison High School coach was arrested on Wednesday after he allegedly engaged in an inappropriate relationship and exchanged nude photos by phone with a female DHS student over a number of months.

Denison Police arrested Tharon Lance Day on a charge of engaging in an improper relationship between an educator and student — a second degree felony in the state of Texas.

“It’s certainly a serious accusation and it has been taken seriously by everybody involved — not just us at the police department, but also by the school district and the student’s family,” Denison Police Department Lt. Mike Eppler said Friday.

According to a criminal complaint filed with the Grayson County District Attorney’s office, law enforcement officials first learned of the relationship on April 13 after a Denison High employee contacted Denison Police. The employee told investigators that he had been approached by a student the day before who said he heard rumors of a female student involved in a “sexual relationship” with one of the district’s coaches. The employee said he also interviewed another student with reported knowledge of the relationship the following day and she told him that she had seen at least one message between Day and the female student and that the two had been communicating regularly through the Snapchat messaging platform.

“DHS and DISD administrators investigated the alleged incident and notified the Denison Police Department,” the district said in an emailed statement provided to the Herald Democrat on Friday. “Denison ISD personnel notified the Texas Education Agency to report the incident, according to TEA regulations and requirements.”

On April 16, investigators went to Denison High School to interview the female student who had reportedly been messaging Day. According to the complaint, the student told investigators that she and Day had met at a coffee shop in October 2017 in order to help Day prepare for a Fellowship of Christian Athletes meeting. The student said she and Day exchanged phone numbers and began communication, but the tone of their conversations changed in January.

The student told investigators that she and Day began communicating through Snapchat and they had exchanged nude photos and sexual messages to each other. However, the student advised that she and Day only hugged and never had sex. Investigators examined the student’s phone with her permission and found messages which indicated that Day had been “giving her advice on friends and relationships.”

Investigators interviewed Day, who told them a similar account of how he and the student met. Day said he knew it was wrong for him to have the student’s phone number, but initially said the two only talked about her athletic achievements and her ex-boyfriend.

When investigators asked Day whether the student ever expressed a physical attraction toward him, Day said, “I don’t want to sound cocky, but not like what a lot of those high school girls or even these junior high girls make sly little comments.”

After investigators confronted Day about his sexual messaging, he initially said he “wouldn’t deny it” and that he only sent a single photo of his genitals to the student. Day also said they both had expressed an interest in having sex with each other. When asked whether he sent a photo of his erect penis to the student, Day said, “I ain’t sending no softie.”

Day told investigators that he and the student never had sex, but that their relationship consisted of him being drunk and lonely at night and exchanging nude photos. Day denied having a sex addiction, but told investigators that a “little sex demon” living inside him had gotten the better of him.

In its emailed statement, Denison ISD said Day was no longer employed by the district and that he resigned from his coaching position at Denison High School after district officials became aware of the relationship.

The Herald Democrat was unable to confirm the female student’s age at the time of the relationship, but the criminal complaint included possession of child pornography or promotion of child pornography as possible offenses.

Day was booked into the Grayson County Jail on Wednesday and was released the following day after he posted a $25,000 bond. If convicted, Day could face between two and 20 years in prison.