[s1e1] The Boy On The Bridge Now

: Dr. Kreizler, an "alienist" (an early psychiatrist), believes a serial killer is at work. He conducts a parallel, covert investigation because the police have wrongfully charged a man just to close the case.

(Daniel Brühl): A brilliant but intense psychologist dedicated to understanding the "alienated" minds of criminals. [S1E1] The Boy on the Bridge

The episode establishes the series' dark atmosphere, blending early forensic thinking with the grit of late 19th-century New York. The Alienist Episode 1 Review: The Boy on the Bridge : Dr. Kreizler

(Dakota Fanning): A strong-willed NYPD secretary who becomes a vital asset to the team. an "alienist" (an early psychiatrist)

(Brian Geraghty): The police commissioner who provides covert support for the investigation while trying to clean up police corruption.