I believe you’re right. There is a very interesting article about it on questmag page titled “Hollywood Versus History: Decoding NYC Society’s Past in The Alienist”
To quote just a short part from it "In fact, Cornelius Vanderbilt, who is a character in The Alienist books, had a real-life run-in with the law, explains Daniel Czitrom, author of New York Exposed: The Gilded Age Police Scandal that Launched the Progressive Era (Oxford University Press). According to Czitrom, Vanderbilt’s son-in-law, Robert Crawford, was involved in a wild shoot-out on the street near the family’s mansion. When the police chased down Crawford hiding in Vanderbilt’s home, the business magnate sent for Thomas Byrnes, captain of the Mercer Street Station, requesting $2,000 to invest on his behalf. Leveraging his stock market connections, Vanderbilt quickly turned that $2,000 in to $6,000 as a reward to quell the scandal. ”