St. Louis city and county sue to block new Missouri gun law

St. Louis and adjoining St. Louis County filed a lawsuit Monday seeking to block Missouri's new law barring state and local authorities from enforcing federal gun laws, saying the law would increase the risk of gun violence in a state already drowning in it.

The suit filed in Cole County Circuit Court seeks an injunction to halt enforcement of the law and to overturn it on the grounds that it violates the Constitution's Supremacy Clause, which established that federal law trumps state law. The law, which Republican Gov. Mike Parson signed this month, would subject law enforcement agencies with officers who knowingly enforce any federal gun laws to a fine of about $50,000 per violating officer.