Some 75 active and retired NYPD officers rallied in Brooklyn Saturday to demonstrate their support for quarterback Colin Kaepernick.

The officers wore "#imwithkap" T-shirts and talked and sang in support of the quarterback and his efforts to find another team in the NFL. Kaepernick opted out of his contract with the 49ers this spring, but his politicial activism, most notably his decision to kneel during the national anthem before games last season, has reportedly made several teams wary of signing him.

While most of the officers at the rally were African-American or other minorities, one notable exception was 81-year-old former NYPD officer Frank Serpico, whose whistle-blowing efforts on corruption in the department inspired the 1973 Al Pacino movie "Serpico."