Washington CNN  — 

Former Speaker of the House Dennis Hastert was paying a former student to keep quiet about allegations of sexual abuse from the time when Hastert was a teacher and wrestling coach in Illinois, two sources with knowledge of the federal government investigation told CNN on Friday afternoon.

Hastert was a teacher and wrestling coach in Yorkville, Illinois between 1965 and 1981 before entering politics. Federal prosecutors indicted Hastert on Thursday for lying to the FBI about $3.5 million he agreed to pay to an undisclosed person to “cover up past misconduct.”

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A federal law enforcement official confirmed to CNN early Friday evening that the former student was a male and a minor when the alleged abuse took place. Federal law enforcement officials also said that investigators decided not to pursue a possible extortion case in the matter.

The high school where Hastert worked released a statement earlier Friday denying any knowledge of past misdeeds.

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“Yorkville Community Unit School District #115 has no knowledge of Mr. Hastert’s alleged misconduct, nor has any individual contacted the District to report any such misconduct,” according to the statement.

It also suggested prosecutors have not contacted the school about Hastert’s misconduct.

A friend of Hastert, who has known him since the 1970s, said he spoke with the former speaker Friday morning.

“He perceives himself as the one being wronged” the friend said. “He’s done an incredibly good job for the people, he’s done that and done as well as he could.”

The friend, however, wouldn’t comment on the accusations.

House Speaker John Boehner released a statement early Friday evening, saying “the Denny I served with worked hard on behalf of his constituents and the country.”

But, Boehner said, “I’m shocked and saddened to learn of these reports.”

Initial bail was set at $4,500, a spokeswoman for U.S. Attorney Zachary Fardon said Friday, adding that that was only preliminary and routine in most cases. She said that his first appearance in court, for his arraignment, is expected next week.

But much remains unclear in the seven-page indictment federal officials lodged against the former Republican House speaker. Here are some other remaining questions:

1. Who, exactly, is “Individual A”?

The indictment describes “Individual A” as the subject of Hastert’s “prior misconduct,” but offers very few clues. The best seems to be “Individual A has been a resident of Yorkville and has known Hastert most of Individual A’s life.” The “Individual A” met with Hastert “multiple times” in 2010 and “discussed past misconduct against Individual A that had occurred years earlier.” It was during those meetings, and later talks, that Hastert allegedly agreed to pay $3.5 million.

RELATED: Read the indictment

2. When did the alleged abuse happen?

The indictment reveals only that “Individual A” met with Hastert sometime around 2010 and at one point “discussed past misconduct … that had occurred years earlier.” There’s no indication of how long ago that was, but it may have been years or even decades, as Individual A “has been a resident of Yorkville, Ill. and has known Hastert most of their life,” per the indictment.

On Friday, his former colleagues expressed shock at the indictment, saying there was no whiff of scandal from Hastert during his time in Congress.

“It doesn’t make any sense to me,” said Rick Santorum, who served in the House with Hastert, on CNN’s “New Day.” “It certainly seems very much out of character.”

Former Virginia Republican Rep. Tom Davis, who served in Congress from 1995 to 2008 with Hastert, said Friday he was stunned by the revelations and said Hastert had been elevated to his leadership post precisely “because he was above reproach.”

“In my knowledge, he was a remarkably ethical leader … that’s why he was put there,” Davis said.

3. Why did it take so long to come out?

The indictment lists relevant facts as including Hastert’s time working as a teacher and coach in Yorkville for 16 years. But Hastert was not apparoached by “Individual A” until 2010. From 2010 until 2014, Hastert first negotiated with and then made secret payments to the unknown subject.

But charges were not filed against Hastert until Thursday, a half century after the first relevant date listed in the indictment.

CNN’s Joshua Gaynor, Evan Perez and Gloria Borger contributed to this report.