Though he has several notable credits from television shows like Law & Order: SVU and True Detective, John is best known for his performances on stage. He’s earned several awards and nominations, including a Tony nomination in 2007 for his role in a play called Radio Golf.
In Season 5, Episode 2, John portrays Horace, the father of main character Dr. Floyd Reynolds (Jocko Sims). During the episode, Floyd confronts his father and his past in the process.
Source: https://www.distractify.com/p/new-amsterdam-season-5-guest-stars