The grieving dad of John Castic, the 27-year-old Goldman Sachs analyst who mysteriously turned up dead in a Brooklyn creek this week, said Friday that his son died by drowning—not from an allergic reaction to peanuts, as he suggested on Wednesday. Castic said his son’s “official cause of death is drowning” in a phone interview with the New York Post, adding that the family “had very low information” when he speculated about Castic’s allergy. Castic’s death remains a mystery, however, as authorities are scrambling to understand how the financial analyst went from enjoying a concert at the Brooklyn Mirage with friends to being dead and alone in a nearby creek. Security cameras captured what was likely Castic’s final moments alive, showing him walking calmly along Stewart Avenue from the venue, not far from where his body was recovered on Tuesday.