A Chester County man was sentenced last week to a term of 339 to 690 years in prison for "one of the worst criminal cases in the history of Chester County." The sentence, handed down at the Chester County Courthouse in West Chester, is believed to be the longest term for any criminal case in county history.

 On June 17, Warren Earl Yerger, Sr., 52, was sentenced by Judge William Mahon for sexual assault of four children over two decades, beginning when some of them were infants.

In her sentencing statement, Deputy District Attorney Deborah Ryan wrote, "This abuse amounted to a decades-long reign of terror and humiliation for these children. Through every degrading act he forced upon these innocent children, the defendant has earned a sentence that resonates through the fabric of our society."

The case against Yerger began in December 2012, when one of his four grown victims contacted police. Between 1989 and 2012, Yerger abused the four children -- three girls and a boy, two of them his biological children -- while moving to four counties in Pennsylvania, from Phoenixville to Spring City, Lower Pottsgrove and elsewhere. The abuse began while he was living in Chester County.

In December 2014, after testimony from three of the children, now adults, Yerger was found guilty of 155 counts of rape, involuntary deviate sexual intercourse, aggravated indecent assault, corruption of minors, endangering the welfare of children and  conspiracy. Yerger is also accused of abusing two women, who joined in the abuse of the children. Deborah Keeley, 49, has been imprisoned for 22 to 44 years. Leslie Yerger, 46, is awaiting sentencing.

Yerger, who maintained his innocence at his trial and has shown no remorse, is accused of sexually abusing all four children, beating them and the two women, locking them in their rooms and keeping them away from food, and killing their pets in front of them to intimidate the children.

In her statement, Deputy District Attorney Ryan wrote, "The defendant was able to continue these despicable acts with impunity because every single adult in their lives participated in the abuse or looked the other way and failed to do the right thing. ... Ultimately, the scope and nature of the defendant's sexual and physical abuse against four young children justifies a sentence that results in the defendant's incarceration for the rest of his natural born life."

On June 17, District Attorney Thomas P. Hogan sent out word of Yerger's historic prison term. "Outstanding work by Deputy District Attorney Deb Ryan, Assistant District Attorney Tony Rock, and the Pennsylvania State Police," Hogan wrote.