LOS ANGELES >> In October 2018, two weeks after he was arrested by the FBI, William “Rick” Singer pulled out his iPhone and wrote about a “loud and abrasive call” with his handlers.

“They continue to ask me to tell a fib,” he wrote, “and not restate what I told my clients as to where (their) money was going — to the program not the coach and that it was a donation and they want it to be a payment.”

Today made for an eventful day in a college admissions scandal that has riveted the nation: A judge set an Oct. 5 start date for a blockbuster trial featuring Lori Loughlin and other parents charged with defrauding the University of Southern California, and notes emerged showing Singer had written that his FBI handlers wanted him “to bend the truth” and tell his clients that payments they made to his charity were bribes, not donations to university athletic programs.

At the heart of the case is this question: Did Singer’s clients believe their payments were bribes that would induce college coaches and officials into accepting their underqualified children, swindling the schools of their employees’ honest employment? Or did they think the payments were genuine donations, routed through proper channels and no different than the checks deep-pocketed parents often write to universities they hope to see their children attend?

It is a question that likely must be settled at trial, which U.S. District Judge Nathaniel M. Gorton on Thursday scheduled to begin with Loughlin, her husband, Mossimo Giannulli, and others charged with defrauding USC.

In his iPhone notes, which prosecutors disclosed to defense attorneys on Wednesday, Singer wrote that his handlers insisted he “tell a fib and not restate” what he had previously told his clients: that their money was destined for a school’s athletic program, not the coach personally, “and that it was a donation.”

“Essentially,” Singer wrote, “they are asking me to bend the truth which is what they asked me not to do when working with the agents and Eric Rosen,” the case’s lead prosecutor.

Jack Pirozzolo, who represents William McGlashan Jr., seized on Singer’s notes in court papers filed Thursday, saying they show prosecutors and agents told Singer to “manufacture evidence” that would support a bribery case “when no such case existed.” A spokeswoman for the U.S. attorney’s office in Boston declined to comment.

Sean Berkowitz, who represents Loughlin and Giannulli, called Singer’s notes “devastating to the government’s case.” Their disclosure, 16 months after a member of the prosecution team first saw one of them, shows the government has adopted a “win at all costs effort,” Berkowitz wrote, “rather than following their obligation to do justice.”

Berkowitz asked a judge to force the U.S. attorney’s office in Boston to turn over every FBI report of Singer’s interviews. He also requested a hearing to determine how the prosecution team learned of Singer’s iPhone notes, why they were withheld and whether the government is holding back any other evidence.

A member of the prosecution team first saw one of the iPhone notes in October 2018, prosecutor Rosen told defense attorneys in a letter dated Wednesday. Prosecutors believed the notes were protected by attorney-client privilege but didn’t begin reviewing whether they were, in fact, privileged until August, Rosen wrote. Singer’s attorney waived that privilege earlier this week, Rosen said.

Berkowitz called this “incredible on its face.” It strains belief, he wrote, to think that “on learning that the supposed mastermind at the center of a vast conspiracy involving dozens of university officials and public figures keeps notes of his daily interactions on his phone,” agents and prosecutors “responded by not reviewing these notes for evidence.”

Gorton, the judge overseeing the case, divided the 15 parents who have pleaded not guilty into two trial groups: the first, slated to begin Oct. 5, includes Loughlin and Giannulli, along with Robert Zangrillo, a Miami investor; John Wilson, a Massachusetts financier; Homayoun Zadeh, a USC dentistry professor; Gamal Abdelaziz, a casino executive; and Diane and Todd Blake, a San Francisco Bay Area couple.

The second trial, scheduled to begin Jan. 11, includes McGlashan, a former private equity chief; David Sidoo, a Canadian investor and former professional football player; I-Hsin “Joey” Chen, who owns a shipping company in Southern California; Elizabeth Kimmel, a media executive; Marci Palatella, chief executive of a liquor company; and Gregory Colburn, a Palo Alto oncologist, and his wife, Amy.