NEW YORK — Robert De Niro’s grandson Leandro De Niro Rodriguez died of a fentanyl overdose after buying laced pills, according to his mother. Drena De Niro, the adopted daughter of the actor and his first wife, Diahnne Abbott, announced De Niro Rodriguez, 19, had died Monday, a day after his body was found at an apartment in the Financial District. Police sources and a doorman told the Daily .