Woman accused of selling lethal fentanyl-laced pills to Robert De Niro’s grandson warned undercover cop to ‘be careful’ with the drugs: ‘My friend...

NEW YORK — A young woman accused of selling the fentanyl-laced fake oxycodone pills that killed Robert De Niro’s teenage grandson warned an undercover cop not to take “more than one at a time” before her arrest because, she said, her friend had “just died,” authorities revealed after she appeared in court Friday.

Wearing a black T-shirt and white sneakers with the laces taken out, Sofia Haley Marks, 20, of Manhattan, was held without bail at Manhattan federal court a day after her arrest on charges alleging she dispensed the pills that caused Leandro De Niro Rodriguez’s overdose death.

The petite Marks combed her hair with her fingers as U.S. Magistrate Judge Ona T. Wang read aloud the charges. She faces one count of distributing and possessing with intent to distribute fentanyl and alprazolam and two counts of distributing and possessing with intent to distribute fentanyl, each carrying 20 years of prison time.

The 19-year-old De Niro Rodriguez, an actor like his grandfather and mother, Drena De Niro, was discovered dead inside a Financial District apartment on July 2, where authorities found cocaine and prescription pills. He’d appeared in three films in his short career, including 2018′s “A Star Is Born” led by Bradley Cooper and Lady Gaga.

Marks was arrested Thursday after selling fentanyl-laced pills to an undercover cop, in possession of 156 counterfeit oxycodone pills and approximately $1,500 in cash, according to the complaint. She sold the undercover officer 50 pills between July 9 and the night of her arrest.

“[P]lease be careful with these,” Marks told the cop, according to the complaint. “[D]on’t do more than one at a time ... my friend just died.”

According to court papers, authorities believe Marks was referring to another 19-year-old who died on June 14. She told the undercover she was present for his overdose and that they had snorted pills together off her phone before falling asleep. When she woke up, the young man was non-responsive.

Less than two weeks later, Marks communicated with De Niro Rodriguez by text between June 29 and July 2 about selling counterfeit oxycodone pills and Xanax, according to court papers.

De Niro Rodriguez texted Marks saying he had lost “all the thirties” — slang for counterfeit oxycodone pills that are blue and stamped with “M” and “30″ — and wanted to buy three more.

“[Do] you [really] need them,” Marks responded on June 30. “[I don’t] wanna kill u.”

Marks later clarified, “I j[ust] don’t like serving u them cuz they not script,” referencing prescription medication.

The next day, Marks followed up to see if De Niro Rodriguez was still interested when he asked her, “[a]re they all fent or h,” and Marks responded that they were “pressies,” referencing a pill press used to manufacture fake drugs, according to the complaint. He also asked her if she had “Zan,” referencing Xanax.

During the back and forth, Marks darkly told De Niro Rodriguez, “[d]on’t go overboard w[ith] these,” according to the complaint. On July 1, she arranged to sell him three counterfeit oxycodone pills and two “bars” of Xanax for $105, agreeing to send them downtown via car service packaged inside a U.S. Postal Service envelope.

Hours after the sale, Marks followed up with De Niro Rodriguez at 1:50 a.m. on July 2, asking, “u good?” She never heard back.

“At least one of Marks’s counterfeit pills was purchased and taken by a teenager who subsequently died of a suspected overdose. The arrest was critical because, as we allege, Marks knew the pills could kill, and she continued selling them anyway,” Manhattan U.S. Attorney Damian Williams said in a statement, adding the investigation was ongoing.

“Fentanyl is now the number one killer of Americans between the ages of 18 and 49. More than cancer, car accidents, or gun violence. It is a law enforcement crisis and a public health crisis.”

According to an NYPD source, Marks had been on the Midtown South Narcotics squad’s radar for some time, and they suspected she had been selling pills laced with fentanyl to teens as young as 15.

She was “known in the drug dealing world,” the source said.

Assistant U.S. Attorney Matthew King successfully requested that the judge remand Marks to custody while her case unfolds. Her federal public defender, Amy Gallicchio, said her family planned to hire private representation, who will make a bail application at a later date. Gallicchio had no comment after the hearing.

Marks is next scheduled to appear in court on Aug. 14, when the court will conduct a preliminary hearing unless a grand jury indicts her in the meantime.

De Niro Rodriguez’s mom, the adopted daughter of De Niro and his first wife, Diahnne Abbott, has published a series of heartfelt Instagram posts since her son’s tragic passing.

“You were so deeply loved and appreciated and I wish that love alone could have saved you,” Drena De Niro wrote July 2.

“I’m so sorry my baby, I’m so sorry.”