He played officer, later detective, Stuart Gharty on Homicide: Life on the Street (1996–1999), and Judge Daniel Phelan in The Wire (2002–2008).
In early 1992, he performed to critical acclaim on Broadway in Conversations with My Father, starring Judd Hirsch, and in Harold Pinter's Hothouse.
[2] In the late 1990s, he joined the cast of the Barry Levinson produced NBC police drama Homicide: Life on the Street.
He played Louis Piquett in Public Enemies (2009), directed by Michael Mann, and had a small part in Mel Gibson's Get the Gringo (2011).
In 2017, Gerety plays Otto Bernhardt, the patriarch of the Amazon Prime series Sneaky Pete.