(ANSA) - ROME, APR 30 - Andrea Sempio on Thursday rejected investigators' assertion that he stabbed to death Chiara Poggi at Garlasco near Pavia in August 2007 because he hated the 26-year-old economics graduate after she rejected a sexual advance by him. Pavia prosecutors gave this as a motive for the murder in a summons for Sempio, 38, to appear before them for questioning on May 6. The Poggi case has long gripped the attention of the Italian public, especially since it was reopened last ye...