The Essex County prosecutor's office says 34-year-old Kasia Rivera gave 22-year-old Justin Street the injection on May 5. Such injections often are used to enlarge body parts, such as the buttocks.
Street died the day after his injection. His death was ruled a homicide following an investigation and a medical examiner's determination he died of a silicone embolism.
Rivera also faces charges for the unauthorized practice of medicine. She was arrested Friday and is being held on $75,000 bail. It's unclear if she has a lawyer. No telephone listing could be found for her home in East Orange.