Bishop Robert Finn of Kansas City, Mo., has been charged with failing to report the suspected abuse of a child, making him the first active bishop in the United States to face criminal prosecution over the sexual abuse of children by a priest.

The Diocese of Kansas City-St. Joseph has been charged with the same offense, which is a Class A misdemeanor, Jackson County Prosecutor Jean Peters Baker announced Oct. 14.

“The fact that this is a misdemeanor count should not diminish the significance of the case,” Peters Baker said in a statement.

“Now that the grand jury investigation has resulted in this indictment, my office will pursue this case vigorously because it is about protecting children,” she said. “I want to ensure there are no future failures to report resulting in other unsuspecting victims.”

Finn, 58, and the diocese both entered pleas of not guilty, according to diocesan spokeswoman Rebecca Summers. The misdemeanor is punishable by up to a year in prison and a $1,000 fine for an individual; the maximum fine for a corporation is $5,000.

“Bishop Finn denies any criminal wrongdoing and has cooperated at all stages with law enforcement, the grand jury, the prosecutor’s office,” Gerald Handley, the bishop’s attorney, said in a statement. “We will continue our efforts to resolve this matter.”

Finn said in a statement: “We will meet these announcements with a steady resolve and a vigorous defense.”

Finn is the highest-ranking Catholic official charged with covering up the sexual abuse of children since the scandal erupted in Boston in 2002.

“As far as we know this is the first time a bishop has been indicted on this type of charge,” said Mar Munoz-Visoso, a spokeswoman for the U.S. Conference of Catholic Bishops.

Last February, Monsignor William Lynn, the former vicar for clergy in the Archdiocese of Philadelphia, was charged with endangering the welfare of children for allowing “dangerous” priests to remain in parishes, according to a grand jury indictment.

The charges against Finn represent a major setback for efforts by the U.S. bishops and the Vatican to put the scandal behind them.

Instead of focusing on what the church has done to change its policies to protect children, church leaders will be forced to answer questions about how they police one of their own.

According to the indictment issued by a Jackson County grand jury on Oct. 6, Finn and the diocese had “reasonable cause” to suspect that the Rev. Shawn Ratigan had subjected children to abuse.

By Dec. 16, 2010, Catholic school officials had warned diocesan supervisors of concerns about Ratigan’s behavior with children, and diocesan officials had found hundreds of photographs of children — including sexual images — on his computer, according to Jackson County prosecutors. Ratigan had also violated restrictions placed on him by the diocese, according to the prosecutors.

Finn has acknowledged that he was told of the lewd photographs last year.

But the diocese did not report Ratigan to local police until May 2011, according to the prosecutors. That month, Ratigan was charged with possessing child pornography.

Earlier this year, the U.S. Conference of Catholic Bishops declined to revise its sexual abuse guidelines, despite pressure from some groups who say they are ineffective.

The charges against Finn likely will force the bishops to again address the guidelines at their upcoming meeting in November in Baltimore.

David Gibson contributed to this report.