Who is the tall man in the long overcoat in the story, After Twenty Years?

Unlike the story's other two characters, the reader never learns the name of the tall plainclothes officer in the long overcoat. As with Patrolman Jimmy Wells, the narrator also withholds describing the arresting officer's physical appearance in much detail except for his seeming too tall to be Jimmy. Just as the plainclothesman's overcoat provides a kind of disguise to shield his true identity, it has also let him blend anonymously into the street scene out of which he steps to keep Jimmy's appointment. The author is suggesting that both Jimmy and the plainclothesman naturally belong in the peaceful neighborhood in a way that Bob does not, even though he was originally born in New York. The plainclothesman and Jimmy are paired together in their no-nonsense, no-frills appearances and manner, despite their obviously different noses. The tall man's pug nose suggests a fighter or a tough, but the narrator presents him as another example of an honorable, workaday city officer.