Ramsey County Attorney John Choi said he was holding the archdiocese to account as a corporation on six gross misdemeanor charges and a related civil complaint for failing to stop Wehmeyer's abuse.
Choi said the archdiocese "time and time again turned a blind eye" to what was going on at the Church of the Blessed Sacrament in St. Paul., where Wehmeyer served. He was dismissed as a priest by Pope Francis in March, three years after he was permanently barred from ministry.
"The facts we have gathered cannot be ignored, they cannot be dismissed, and are frankly appalling, especially when viewed in their entirety," the attorney said.
Choi said facts in the case were still being uncovered. St. Paul Police Chief Tom Smith asked anyone with information to come forward.
"This case is not about religion. It's about allegations of misconduct and crimes that were committed," Smith said. "These types of allegations are always disturbing, especially when it involves people in positions of authority and trust."
In January, the Roman Catholic Archdiocese of St. Paul became the 12th U.S. diocese in the U.S. to seek bankruptcy protection in connection with claims of sex abuse by priests.
The case against the archdiocese was prompted in part by a Minnesota Public Radio investigation that uncovered evidence that several church officials did not immediately report allegations of abuse to police.
Minnesota Public Radio has a bit of background: "It began in October 2013 when St. Paul police opened an investigation of the handling of allegations of child sexual abuse [by] Wehmeyer, who was arrested in 2012 and pleaded guilty to sexually abusing two sons of a parish employee and possessing child pornography. He ... is serving a five-year prison sentence."
The Associated Press adds: "Criminal charges against a diocese are rare. But in 2011, a grand jury indicted Bishop Robert Finn and the Diocese of Kansas City-St. Joseph in Missouri on a misdemeanor charge of failing to report suspected child abuse. Finn was convicted in 2012, and he resigned this past April."
A spokesman for the archdiocese didn't immediately return a message from the AP seeking comment on the charges. The news agency says that the six counts are punishable by a fine of a few thousand dollars.