Missouri authorities are drawing up contingency plans and seeking intelligence from U.S. police departments on out-of-state agitators, fearing that fresh riots could erupt if a grand jury does not indict a white officer for killing a black teen.
The plans are being thrashed out in meetings being held two to three times a week, according to people who have attended them. The FBI said it was also involved in the discussions.
Details of the meetings and of the sharing of intelligence by Missouri police agencies and their counterparts around America have not been reported before.