The 20-year-old 'Percocet Princess' who allegedly sold Robert De Niro's grandson drugs before his death warned him that they could potentially kill him before she sold him the pills. Sophia Haley Marks, 20, is accused of selling 19-year-old Leandro De Niro Rodriguez drugs shortly before he was found dead in his New York City apartment. Marks, who has been nicknamed 'the Percocet Princess', was arrested Thursday night at around 6 p.m. in an NYPD undercover sting operation, according to the New York Post. Legal documents say that police found pills at the scene where Rodriguez died and used the teenager's...