Gary D'Addario is an American retired police commander, television technical advisor and actor from Baltimore, Maryland.
[2] D'Addario served as a shift lieutenant in the Baltimore Police Department homicide unit for 10 years during his career.
D'Addario was a technical advisor for Simon's next project, the Emmy Award-winning miniseries The Corner, and had a small role as a desk sergeant.
[3] Simon wrote to Mayor Martin O'Malley to ask if there was any link and seeking confirmation that other city employees did not risk losing their jobs by appearing on the series and received no response.
[3] D'Addario stood down as technical advisor because he was no longer part of the police department[3] but continued to appear on the show until its conclusion.