Mélenchon: "Hang the murderous policeman and his accomplice who ordered him to shoot."

The guard dogs order us to call for calm. We call for justice. Withdraw the legal action against poor Nahel. Hang the murderous policeman and his accomplice who ordered him to shoot. Leave the paramedic alone.

Is "hang someone" an idiom in French? Or is he based and literally calling for the execution of a pig?