ROME—An Italian prosecutor on Saturday requested life in prison for two young American men charged with slaying an Italian police officer in central Rome. Prosecutor Maria Sabina Calabretta asked the court to find the two defendants — Finnegan Lee Elder, 21, and Gabriel Natale-Hjorth, 20 — guilty and to impose Italy’s maximum sentence for the July 26, 2019, stabbing death of Vice Brigadier Mario Cerciello Rega. Calabretta called the attack “disproportionate and deadly.” The defense will make its closing arguments beginning March 18, before the court decides the verdict and sentence. The two Americans were on vacation in Rome when they were confronted by a pair of plainclothes Carabinieri officers at what the pair believed was going to be a meeting with the go-between in a cocaine deal that had gone bad. Elder has claimed self-defense, testifing this month that he stabbed the victim because he feared he was being …