WASHINGTON (AP) — The Justice Department is warning Missouri officials that the state can’t ignore federal law, after the governor signed a bill last week that bans police from enforcing federal gun rules. A top Justice Department official sent a letter Wednesday night saying the Supremacy Clause of the U.S. Constitution outweighs the measure that Gov. Mike Parson signed into law Saturday. The law would penalize local police departments if their officers enforce federal gun laws. Acting Assistant Attorney General Brian Boynton says in the letter that Parson and Eric Schmitt, the state’s attorney general, must clarify the law to the federal government.