The attorney general in the US state of Missouri on Friday accused the Catholic Church of turning a blind eye to church sex abuse and referred a dozen former clergymen for criminal prosecution.

“Sexual abuse of minors by members of Missouri’s four Roman Catholic dioceses has been a far-reaching and sustained scandal,” said the Midwestern state’s top prosecutor, Eric Schmitt, after a year-long investigation.

“For decades, faced with credible reports of abuse, the church refused to acknowledge the victims and instead focused their efforts on protecting priests,” Schmitt told a news conference.

He said the probe into diocese records across the state revealed that 163 priests or other members of the clergy had been accused of sexual abuse or misconduct against minors.

Around 80 of the accused are already dead, but the attorney general said he will refer a dozen men for prosecution by local authorities.

“The standard response to reports of abuse by church leadership was to move an offending priest into a short-term period of treatment and then reassign him to public ministry in a new parish,” Schmitt said.

“Members of an offending priest’s old and new parishes were not notified of the reason for a transfer in these cases. At best, victims were offered limited counseling services to help recover from the abuse.”

A spokesman for Schmitt’s office told The New York Times that investigators had heard from more than 100 victims of abuse and had spoken directly to 45 victims or their families.

“We did have one priest who had 21 victims come forward, so we can assume the number is in the hundreds,” said the spokesman, Chris Nuelle.

The Vatican is struggling to deal with a global epidemic of sexual assault by priests, in particular of minors. Much of the abuse has gone on for decades.

Faced with widespread criminal investigations, Pope Francis announced in May that every Catholic diocese would have to come up with a plan for reporting abuse.