One of the most controversial provisions of gun legislation passed this year by the state legislature takes effect on Sunday. So-called “constitutional carry” will let Missourians 21 and older who can legally own guns carry them concealed anywhere they can now openly carry, and do so without a permit. Senator Brian Munzlinger (R-Williamstown) sponsored the measure.

Missouri State Capitol in Jefferson City

According to the National Rifle Association, Missouri will join 10 other states with constitutional carry laws.

Another provision taking effect is one that allows local judges and prosecutors on the job to carry a firearm for self-defense with a concealed carry permit.

Under the law, Fire Department personnel will also be permitted to carry a firearm on the job, with approval from their governing body.

A provision that took effect earlier this year includes a so-called “stand your ground” component, which allows deadly force to be used without retreating by a person who thinks a reasonable threat exists. The NRA says 30 states have laws or court rulings which allows such form of self-defense.

Another portion of the law already underway expands Missouri’s “castle doctrine”, which lets people who are guests in a home use deadly force to defend themselves and others in that home.

Opponents of the law argue that people should be trained to know how to safely handle a gun. Some have also contended that the law will let people legally carry a concealed firearm, even if they have been denied a concealed carry permit by a sheriff because a background check revealed criminal offenses or the sheriff believed the individual poses a danger.

Supporters say the law does not make it legal for convicted felons to obtain or carry a firearm in Missouri.