On June 1, 2013, a new law will go in effect in St. Louis City allowing Police Officers to charge individuals with 35 grams or less of marijuana with a municipal ordinance violation instead of it being a criminal infraction. Under the current laws in effect, a first offense is Class A misdemeanor, punishable by a $1000 fine and 1 year in jail. The new penalty will be a fine of $100-$500 and up to 90 days in jail. Instead of being handcuffed and arrested, violators will likely get a summons to appear in municipal court.
For more information you can read this article in the St. Louis Post Dispatch.