By John Derbyshire On Monday December 19, another Muslim murderer ran amok: twenty-three-year-old Tunisian immigrant Anis Amri hijacked a big rig and drove it into a crowd of Christmas shopper s in Berlin, Germany, killing twelve and injuring fifty. Three and a half days later, in the small hours of Friday morning, Amri was spotted by two cops in Milan, Italy. They accosted him; he shot and wounded one of the cops; the other cop then shot him dead. Amri’s immigration history is a case study of Western stupidity and incompetence. He was one of the early boat people leaving North Africa for the Italian island of Lampedusa in 2011. While there he was arrested for robbery, and arson—he helped set fire to a holding center for illegals. The Italians put him in jail for four years. In Italian prisons,…