When the FBI came calling early on a rainy morning in December 2014, Dennis Hastert’s wife answered the door.

The authorities hadn’t warned the former speaker of the U.S. House of Representatives they’d be visiting his Plano home that day. They just showed up, secretly wired, at 8:15 a.m., records show.

But the once-powerful Republican didn’t seem particularly surprised, FBI Special Agent Lisa Strong, one of the two lead agents on the case speaking publicly for the first time about Hastert, told the Chicago Sun-Times. He’s “accustomed to talking to a lot of people,” Strong said.

The agents asked for “Mr. Hastert.” They wanted to speak to him about the massive amounts of cash Hastert had taken out of his bank accounts, raising their suspicions.

Strong, who had never seen the popular politician in person, soon found herself in his living room, having a cordial conversation. It began with a question: “Are you and your family safe?”

Their talk lasted less than an hour, Strong says. And though records show Hastert was told, “They do have enough evidence to charge you,” the agent said the conversation wasn’t adversarial.

Still, because of the lies Hastert told that day, it forever changed the way history will view the longest-serving Republican speaker of the House.

A year has passed since federal prosecutors revealed explosive allegations that Hastert, now 75, had sexually abused five students decades ago, while he was Yorkville High School’s celebrated wrestling coach. The claims — made in a court filing on April 8, 2016 — were a prelude to the dramatic, two-hour hearing later that month that left Hastert with a 15-month prison sentence for a financial crime he committed while trying to cover up the abuse.

In an exclusive interview with the Chicago Sun-Times, Strong and Special Agent Joe Guest of Internal Revenue Service Criminal Investigations spoke about the significance of the lies Hastert told during his Dec. 8, 2014, interview.

And they revealed for the first time that Hastert had been on the FBI’s radar as early as November 2012 — even before the FBI and IRS began investigating the suspicious cash withdrawals that were Hastert’s downfall.

“I think it’s important for everybody to understand that no one’s above the law,” Strong said. “And it doesn’t matter if you happen to be a person who used to create the law. You’re not above the law.”

Hastert lawyer Thomas Green wouldn’t comment, except to call the Sun-Times interview of the two agents “unusual.”

Hastert already has served nearly two-thirds of his sentence. He is due to leave prison by Aug. 16, though it’s possible he could go free earlier.

There were plenty of questions the agents wouldn’t answer. They cited an ongoing court fight in a civil case, for instance, declining to speak about the person prosecutors called “Individual A,” whose $3.5 million hush-money deal with Hastert was central to Hastert’s indictment. Hastert accused Individual A of extortion, but prosecutors have said Individual A “committed no crime.” U.S. District Judge Thomas Durkin even called Hastert’s accusation “unconscionable.”

Strong said “the case started in 2013” — that’s when records show the FBI and IRS began investigating Hastert’s cash withdrawals.

Hastert previously had been dogged by questions about the use of his taxpayer-funded Office of the Former Speaker for private business. That’s what first brought him to Strong’s attention. Strong said her boss at the time dropped a newspaper article on her desk about Hastert’s dealings in November 2012 and said, “Here’s your next case.”

But Hastert was never charged in connection with the use of his post-congressional office. And a lawsuit that a suburban businessman filed in 2013, claiming Hastert used that office to do private business with him, was dismissed Thursday.

More than two years later, Strong visited Hastert at home in Plano.

Said Guest: “With any case, you just have to follow where the investigation leads.”

Early in 2015, records show the agents learned Hastert had struck a deal in 2010 to pay millions to Individual A because Hastert had molested him in a motel room when Individual A was 14. But when the FBI interviewed Hastert in December 2014, Hastert told the agents he was only keeping his money in a safe place.

Later, asked about this in court, Hastert told the judge he “didn’t want them to know how I intended to spend the money.”

“What I did was wrong, and I regret it,” Hastert said before he was sentenced.

Guest said Hastert’s lying to the agents was a crucial moment in the investigation.

Durkin echoed that in sentencing Hastert, telling him, “If you told the truth, I’m not sure we’d be here today.”

“If we go to talk to somebody and they lie to us, yes, that’s a turning point,” Guest said. “That’s why it’s important, when we investigate people, we expect them to tell us the truth. And if they don’t, of course, that charge is there for a reason.”

Hastert was charged in May 2015 with lying to the FBI, as well as the financial crime. His seven-page indictment said nothing about sexual abuse.

Though word of that leaked out, it was another 10 months before federal authorities revealed they had found five victims.

Strong called the Hastert investigation an “all-consuming” case that “took a tremendous amount of time.”

And when key revelations made their way into the news — like the sexual abuse allegations revealed one year ago — the agents said they were watching to see how it was covered.

“This was a huge case, just in general,” Strong said. “So any of the court filings were important to us, and we paid attention to that.

“We lived this case.”

READ MORE:

Hastert seeks $1.7 million in hush money repayment, Jan. 20, 2017

Forty years after abuse, Dennis Hastert due in prison, June 22, 2016

Dennis Hastert, ‘serial child molester,’ gets 15 months in prison, April 27, 2016