St. Louis city and county have filed a lawsuit over Missouri’s new gun law. The suit filed yesterday (mon) argues that the Republican-backed law would increase the risk of gun violence. The new law would subject law enforcement agencies to fines and legal action if they enforce federal gun rules. A federal official sent a letter to the state last week saying the U.S. Constitution’s Supremacy Clause trumps state law. But Missouri Attorney General Eric Schmitt said last week they still plan to enforce it.