Updated

Missouri Gov. Jay Nixon is reaching out to St. Louis-area clergy in advance of a grand jury announcement on whether a white police officer will be charged for fatally shooting a black 18-year-old.

The announcement expected Monday evening comes more than three months after Ferguson officer Darren Wilson shot Michael Brown, triggering weeks of protests.

The Rev. Ronald Bobo Sr. says he and other clergy have been invited to participate in a conference call with the governor.

Nixon also was to hold a 5:30 p.m. news conference at the University of Missouri-St. Louis with the state public-safety director and St. Louis city and county officials. The governor's office says Nixon is calling for peace and outlining "preparations to protect the public and free speech" if more protests occur.