The Supreme Court ruled in favor of Ali Hemani, a Texas man charged with unlawful possession of a gun, since he admitted that he regularly smoked marijuana.
Two people have been charged in connection with a north suburban school resource officer's gun that went missing earlier this week.
Classes have been canceled Tuesday at Forest View Educational Center in Arlington Heights after a school resource officer lost a firearm in a restroom, the school said.
Trump's Republican administration alleges the ban violates the Constitution's Second Amendment right to bear arms.
Pirro said there is evidence that buckshot from a shotgun carried by alleged White House Correspondents' Dinner attacker was "intertwined with the fiber" of a bulletproof vest worn by a Secret Service officer.
The first count of attempting to assassinate the president carries a maximum sentence of life in prison if convicted.