An alleged drug dealer known as the “Percocet Princess” has been arrested for allegedly selling Robert De Niro’s grandson Leandro a fentanyl-laced pill before his death.

Sofia Haley Marks, 20, allegedly sold Leandro De Niro Rodriguez drugs before he was found dead in his Financial District apartment on July 2, The New York Post reported. She was arrested around 6 p.m. on Thursday, during an undercover sting operation conducted by the NYPD, Drug Enforcement Administration and Homeland Security, the paper said, quoting sources.