A former member of the Arcadia High School student council, Dylan Chan, was arrested after detectives searched his home last week. The 18-year old faces charge of sexual exploitation of a child, using a minor for sex acts and distribution of child pornography.
A former classmate who is using the name "Judy" to protect her privacy said that she was 17 when Chan had sex with her, recorded it without her consent, then posted it on social media.
"As I first found out, I just couldn't believe that he would do something like that to me," said Judy.
Because of an earlier experience, she said she didn't feel Arcadia High School administrators would take her seriously if she reported it to them. She said classmates urged her to keep silent.
Former student arrested in Arcadia High School sexual assault investigation
"Just telling me that would ruin his life if I did that and calling me back (saying) he would change," said Judy.
Seven months later she took evidence of the illicit social media posts to Arcadia police. She also addressed her classmates in an online letter, calling them out for failing to condemn the activity which she said was carried out by multiple male students.
"It was a pretty open secret in our high school, like kind of everyone knew about this chat," said Shria, a recent Arcadia High School graduate who wants to keep her last name private.
Acting as whistleblowers, Shria and classmate Hailey described the online activity they witnessed and the difficulty as teenagers in reporting it.
"I was definitely very intimidated, especially because these people sat next to me in classrooms. So many people were friends with them," said Hailey.
The newly graduated teens said that they had alerted the school and police investigators long ago.
Police Capt. Paul Foley said last week he had no knowledge of a report that the pair made last June. But now upon further investigation, he said, he found the recorded report and said the department is conducting an internal investigation into what happened with that call.
Two years ago, when Hailey was a sophomore, she reported to the dean that boys including Chan were soliciting nude photos on SnapChat. She said if Chan was disciplined at that time, the punishment was not serious enough to be noticed by classmates or deter further activity by Chan.
A school spokesman, Ryan Foran, said privacy laws prevent discussion of school matters.
"We are continuing to hear and listen to our students and are supporting them in every way possible, even when possible misconduct did not take place on school premises or with school property," Foran said in a written statement, which also included a list of resources for students.
The whistleblowers said more must be done to support young women who are shamed and harassed.
"Because a lot of girls feel scared to come and report, because a lot of the blame is put back on the victim," said Hailey.