United States v. Lopez

Congress passed the Gun-Free School Zones Act (GFSZA) making it a federal crime to knowingly possess a firearm in a place known or reasonably believed to be a school zone. Lopez (defendant), a student who brought a gun to his high school, was arrested and convicted under the GFSZA; he challenged the statute as exceeding Congress's Commerce Clause authority, the Fifth Circuit agreed and reversed his conviction, and the Supreme Court granted certiorari.