A longtime Ridley High School physics teacher and track coach was arrested on institutional sexual assault charges for his relationship with an 18-year-old female student at the school.

Delaware County District Attorney Jack Whelan said in a press release that Gregory A. Stanczuk, 52, of Birmingham Township, was taken into custody on Friday, Feb. 19, following a three-week investigation by Sgt. Robin F. Clark of the Delaware County District Attorney’s Criminal Investigation Division Child Abuse Unit.

On Jan. 29, Clark received information that Stanczuk, a physics teacher of more than 30 years and head girls’ track and field coach, had initiated an inappropriate relationship with a female student when she was a senior. The girl, a member of the track team for four years, had Stanczuk as a teacher her freshman year, the release said.

According to the victim, she and the coach began spending a lot of time together after she broke up with her boyfriend. During that time, she told detectives that she was in a vulnerable state because of the breakup, the release said.

She told detectives that she confided in Stanczuk and considered him a trusted friend. When Stanczuk drove students home after practice, he would drop off the victim last, and they would be alone in the car together. During those times they would talk about her breakup, and he would try and comfort her by giving her a hug, according to the release.

As time went on, they began texting each other, and Stanczuk would tell the victim how similar they were and that no one understood her like he did. In the spring of 2014, they were driving around talking and ended up in Ridley Creek State Park where Stanczuk pulled her in and kissed her. The girl reportedly became upset, prompting Stanczuk to say: “If you don’t want me to do that, we don’t have to,” the release said.

Following that day, they continued to drive around and he would often hold her hand. Stanzcuk told the victim that she made him feel young. On one occasion he drove through his own neighborhood in Birmingham Township with the victim in the car, driving past his house because “it gave him adrenaline to do so,” the release said.

One time, Stanczuk sent the victim a text around 2 a.m. asking if she wanted to meet at a hotel. She eventually agreed, and he picked her up in his car. The victim told detectives that in the hotel room, they started kissing and got undressed. After performing oral sex on her, he wanted to do more, but she became upset, stating: “You have a wife and kids.”

The next day at school, she and Stanczuk joked about the previous night at the hotel, she told detectives, adding that she would “feel sick” when she thought about what had happened.

She said another incident occurred in June 2014 when the track team went to nationals in Greensboro, N.C. One night after Stanczuk had given her three or four beers, he made a pass at her in his hotel room. When she responded that she had a boyfriend, he said: “So what, he doesn’t have to know,” the release said, adding that the victim started crying and left the room.

“As a teacher and coach, Gregory Stanczuk flagrantly used his position of trust and authority to exploit the victim, manipulating her emotionally for his own sexual gratification,” Whelan said in the release. “He crossed the line between teacher and student and committed a crime by engaging in sexual behavior with his student.”

Whelan commend Det. Sgt. Robin Clark along with Deputy District Attorney Michael Galantino, who will be prosecuting the case, for their work on the case, the release said.

Stanczuk was arraigned and failed to post 10 percent of his $100,000 bail. He will be processed and then transported to prison to await a preliminary hearing, according to court officials.

The release suggested that any parents who believe their child was victimized they should contact Clark at 610-891-4118.