Roberti served as National anti-mafia and anti-terrorist prosecutor from 2013 to 2017. During his time in office, he led a 2016 effort of Italian, Colombian and U.S. police to seize 11 tonnes of cocaine and arrest 33 people from a mafia-linked ring which refined the drug in the jungles of Colombia and smuggled it out in containers of tropical fruits. He also worked to ensure the mafia is blocked from playing any role in reconstruction after the August 2016 Central Italy earthquake that killed nearly 300 people.