CHICAGO — A federal judge has sentenced Dennis Hastert to 15 months in prison in a hush-money case that centered on accusations that the former U.S. House speaker sexually abused at least four students when he was a high school wrestling coach.

Judge Thomas M. Durkin announced the sentence Wednesday. Hastert also must undergo sex offender treatment, two years of supervised release after his time behind bars and a $250,000 fine to go to a crime victims fund.

He pleaded guilty last fall to violating banking law as he sought to pay someone referred to as Individual A $3.5 million to keep sex abuse secret.

Before he sentenced Hastert, Durkin described the 74-year-old Illinois Republican as a “serial child molester,” and that “accusing Individual A of extorting you was unconscionable.”

He was the nation’s longest-serving GOP speaker and was second in the line of succession to the presidency.

Hastert’s attorney Thomas Green released the following statement:

“Mr. Hastert accepts the sentence imposed by the court today. As he made clear in his own words in addressing the court, he takes sole responsibility for this tragic situation and deeply apologizes to all those affected by his actions. He hopes that he now can focus on addressing his health issues and on healing the emotional damage that has been inflicted on his family and friends who have shown unwavering support throughout this trying time.”