1. Examples
Byron from Iowa is arrested by Keats, an Iowa police officer. Byron claims Keats used excessive force and sues him under a federal civil rights statute.
Byron also files a state law claim for battery, arising from the arrest.
Can the federal court hear both claims?
It emerges that Keats was an old friend of Byron and owes him $500. Byron asserts a third claim for the debt as part of the action. Can the federal court hear it?
Byron from Iowa is arrested by Keats, an Iowa police officer. Byron claims Keats used excessive force and sues him under a federal civil rights statute. > Federal courts have jurisdiction as this is a federal question, it arises under federal law.
Byron also files a state law claim for battery, arising from the arrest. > If this was filed alone there would not be federal jurisdiction, as there is no diversity and it is not a federal question.
Can the federal court hear both claims if Byron files them together? Yes, it has subject-matter jurisdiction in the first claim, so it can exercise supplemental jurisdiction over the related state law claim.
Nonetheless it is not obliged to hear the case, if it feels that a state court is a more appropriate venue, it can dismiss the claim or remand it to state court.
However, the debt claim is not clearly linked or related to the original claim, and will not raise the same issues at trial, so supplemental jurisdiction will not apply.