The Wednesday protest came the week after the release of a report from a Pennsylvania grand jury, which found widespread abuse of more than 1,000 children by more than 300 priests. The report further alleged that the Catholic Church hierarchy worked to cover up the sex crimes for decades.

"We believe we have exactly the same issues as they do in Pennsylvania," Nicole Gorovsky, a former Missouri assistant attorney general, former federal prosecutor and private attorney who specializes in child sexual abuse cases, said on Wednesday.

Representatives with the St. Louis-based Survivors Network of those Abused by Priests said there are at least 170 Catholic clerics who at a minimum have been credibly accused of sex crimes. The group says few have been prosecuted.

Advocates have said Hawley could take action, including coordinating with local prosecutors, filing a civil lawsuit against the Catholic Church, or targeting church officials accused of cover ups.

Hawley said on Thursday that while prosecuting and subpoena authority rested with local law enforcement, his office would still investigate alleged crimes, publish a public report and refer credible cases to local prosecutors.

"While my office does not have jurisdiction at the present time to prosecute any criminal acts of this nature, or again to issue subpoenas to investigate it, it would be possible to conduct a thorough and robust investigation of potential clergy abuse if the various diocese were willing to cooperate," Hawley told reporters.

He said Archbishop Robert Carlson sent a letter this week to Hawley confirming that the Archdiocese of St. Louis "will open to my office their files and allow us to conduct a thorough, impartial review of potential clergy abuse in the Archdiocese of St. Louis."

He did not immediately provide a timeline on how long the investigation would last.

Hawley, a Republican, is running for U.S. Senate this year.