Former Royal Palm Beach High School Assistant Principal Carolyn Brown told The Palm Beach Post it was an "open secret" that female students were involved in something suspicious that involved hundreds of dollars in cash and resulted in girls being bullied for being "prostitutes" and "sugar babies."

What administers didn't know, or at least didn't act upon, was that at least 15 underage girls enrolled at the high school were sexually assaulted by financier and now convicted sex offender Jeffrey Epstein, according to police reports obtained by The Palm Beach Post.

Read more: Jeffrey Epstein reportedly visited the White House several times while Bill Clinton was president

Like dozens of other accusations against the shadowy financier, who is currently being held without bail on charges of sex trafficking of minors and conspiracy in the southern district of New York, Epstein's Royal Palm Beach High accusers say he paid them to give him massages, during which he would coerce them into sex acts.

Epstein was well aware that his victims would have been high schoolers, since The Post reported that a Royal Palm Beach High transcript was found in 2005 in his bedroom desk drawer at his $12 million Palm Beach estate, next to a massage table and an armoire filled with sex toys.

One Royal Palm Beach High accuser told police she was 16-years-old when Epstein asked her to give him a massage while she was topless. She said she told him she was in high school. He asked what her favorite sex position was.

Another 16-year-old told police Epstein said he would help her get into her dream college, New York University, after reviewing her SAT scores and high school transcript.

Epstein also wrote a note on his own Jeffrey E. Epstein-branded stationary, Palm Beach police officers found, which instructed an employee to deliver a dozen roses to an underage girl who performed in a Royal Palm Beach High play. Police found the note in Epstein's garbage in 2005.

These findings were some of the evidence brought forward before Epstein signed a plea deal in 2008 that allowed him to avoid federal prosecution and serve 13 months of an 18-month prison sentence, during which he could work from a high-rise in Palm Beach 12 hours a day, 6 days a week.

Now, Epstein is pleading not guilty to sex trafficking charges that accuse the elite financier of assaulting upward of 80 women, many who were underage at the time of the assault, including some as young as 14. The Palm Beach Post reports that Epstein recruited girls from several Palm Beach, Florida high schools, but that Royal Palm Beach High was his "ground zero."

The Post reports that girls who were part of Epstein's underage sexual assault scheme were bullied for being "prostitutes" and "sugar babies," which administrators took notice of when they found $300 in a girl's purse after she was caught fighting with another female student.

Attorney Adam Horowitz, who has represented some of Epstein's accusers in eight civil lawsuits, was quoted as describing the girls who were allegedly targeted as vulnerable, with some "living in trailer parks," in The Post.

Epstein asked girls to bring their friends, The Post reported, paying girls up to $200 for recruiting new victims. "The younger the better," he instructed them, according to one accuser who was first approached by an adult who worked for Epstein in 2003 at a resort in Riviera Beach.

That accuser went into her senior year at Royal Palm Beach High with Epstein's goal in mind, with The Post reporting she recruited at least eight other underage girls who then recruited their own friends, including some girls who were on the verge of homelessness and needed money, badly.

"Knowing what we know now, it's so sad what happened to those girls," Brown, the former assistant principal, told The Post.