NOVATO (KRON) — Police arrested Novato High School track coach Steven Deschler Thursday on charges of having a sexual relationship with a 17-year-old female high school student, according to police.

The mother of the victim discovered evidence of the sexual relationship between 64-year-old Deschler and her daughter on her daughter’s phone and contacted authorities.

The victim’s mother tells KRON that she was prompted to call authorities after discovering text messages on her daughter’s cell phone from Deschler.

During a 2-hour interview with investigators, the victim told investigators about the relationship. Deschler and the victim had known each other for four years. The victim graduated from Novato High School this year.

At this time, it appears there is only one victim in the case. Investigators are still trying to determine if there are more victims.

Police arrested Deschler Thursday around 11:25 p.m., at the Oakland International Airport as he departed an airplane on a return flight from Hawaii, according to police. Detectives served search warrants at Deschler’s residence in Novato and at his office at Novato High School. His cell phone was confiscated.

Deschler was booked into the Marin County Jail on charges of oral copulation with a minor, sexual penetration of a minor, communicating with a minor with intent to commit a specified sex offense, arranging a meeting and then meeting with a minor for the purpose of engaging in lewd and lascivious conduct.

Deschler was released on $100,000 bail Thursday night.

An emergency protective order was granted by a judge and served on Deschler protecting the victim from any further contact from Deschler.

The victim’s mother, a single parent, said that Deschler was close to the family, often helping them out with offering transportation.

Calls and emails to Novato High School went unanswered due to a scheduled holiday.