Three Missouri police agencies will restrict their use of tear gas and other chemical agents on crowds as part of a lawsuit settlement with six Ferguson protesters.

Court records show that U.S. District Judge Carol Jackson officially dismissed the lawsuit Thursday. But she'll supervise the case through 2017 to ensure the agencies comply.

Protesters sued over the "unified command" that handled security at the protests sparked by the fatal police shooting of 18-year-old Michael Brown in August. The command included the State Highway Patrol, St. Louis County police and St. Louis police.

Jackson issued a temporary restraining order in December requiring police to provide "reasonable" warning before using gas on a crowd.