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."

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.

"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:

Photos: Dennis Hastert's political career Dennis Hastert in 1985 as a member of the Illinois House of Representatives, where he served from 1980 to 1986. Hide Caption 1 of 8 Photos: Dennis Hastert's political career Hastert is sworn in as speaker of the House of Representatives on January 6, 1999, during the opening session of the House in Washington. Hastert replaced Newt Gingrich. Hide Caption 2 of 8 Photos: Dennis Hastert's political career Hastert stands behind President George W. Bush as he signs Medicare legislation in December 2003. Hastert fought hard for the bill in the House, leading to a three-hour vote on November 22, 2003. Hide Caption 3 of 8 Photos: Dennis Hastert's political career House Rules Chairman David Dreier and Hastert hold a news conference on a GOP lobbying reform package, which included banning privately funded travel and eliminating access to the House floor for former members who are registered lobbyists. On January 3, 2006, Hastert donated $70,000 of campaign contributions from companies associated with lobbyist Jack Abramoff to charity after Abramoff pleaded guilty to corruption charges. Hide Caption 4 of 8 Photos: Dennis Hastert's political career Vice President Dick Cheney greets Hastert before Latvian President Vaira Vike-Freiberga speaks to a joint meeting of Congress in June 2006. Earlier that month, Hastert had surpassed Joe Cannon to become the longest-serving Republican speaker of the House. Hide Caption 5 of 8 Photos: Dennis Hastert's political career Hastert celebrates his re-election to an 11th term in Congress on November 7, 2006, with his wife, Jean, at a victory party in the Baker Hotel in St. Charles, Illinois. Republicans lost their majority in the House, meaning Hastert lost his position as speaker when the new Congress started on January 4, 2007. Hide Caption 6 of 8 Photos: Dennis Hastert's political career Hastert announces that he will not seek re-election for a 12th term on August 17, 2007, as he stands on the steps of the old Kendall County courthouse in Yorkville, Illinois. Hide Caption 7 of 8 Photos: Dennis Hastert's political career Hastert walks through Statuary Hall on his way to the House floor to make his farewell address to Congress on November 15, 2007. He formally resigned on November 26, 2007, after 20 years in office. Hide Caption 8 of 8

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.

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.