What is a requirement for federal jurisdiction over a state law claim when accompanied by a federal claim?

The requirement that both claims must arise from the same event or transaction is a key aspect of supplemental jurisdiction under 28 U.S.C. § 1367. When a federal claim is present and a state law claim is introduced, the state claim can be heard in federal court if it shares a common nucleus of operative fact with the federal claim. This allows the court to address all related issues in one proceeding, promoting judicial efficiency and consistency in outcomes.

Options that suggest requirements such as the state law claim involving federal parties, needing to be filed in state court, or the residency of the plaintiff are not necessary conditions for establishing federal jurisdiction over the accompanying state law claim. The primary focus is on the relationship between the claims, which is satisfied when they arise from the same event or transaction.