ROME — Nearly two decades after 26-year-old office worker Chiara Poggi was found dead in her home in the small ​northern town of Garlasco, a case that once seemed closed has been reopened, reviving doubts about one of Italy’s most ‌scrutinized murder investigations. The case has become a closely followed psychodrama in newspapers and on television, highlighting a potential failure of the Italian justice system , and is back under the spotlight as the man convicted of the crime nears the end of his sentence. Poggi’s student boyfriend, Alberto Stasi, was definitively convicted of her killing in 2015 ​and sentenced to 16 years in jail, apparently bringing the curtain down on a tragic story that had captivated the country ​from the start. 26-year-old office worker Chiara Poggi was found dead in her home in the small ​northern town of Garlasco, Italy nearly two decades ago.…