There was a TV series, in the early 1990's called "The Untouchables" (meaning these law enforcers couldn't be touched by bribes), roughly based on the 1987 movie with Kevin Costner (I thought the movie was pretty bad) which was about the 1920' /30's Chicago mobster Al Capone and the U.S. Department of Treasury Law Enforcement officer Eliot Ness.
It was a historical crime drama TV show; I think the series lasted two or three seasons, and then ended.
Some of the supporting actors went on to become famous or popular actors, most notably John Rhys Davies who played the role of Captain Malone, who later starred as the Dwarf Gimli in the 'Lord of the Rings' films:
YouTube - The Untouchables - Series Intro
If you watched the show on TV, immediately after the show's intro, they would show the same still at the end with the five Untouchables, and the announcer would say "Brought to you by Toyota: I love what you do for me".
There were a few interesting episodes where they showed some important historical events, including the assasination attempt on Franklin D. Roosevelt in the 1930's and and Thomas Dewey when he was a Prosecutor in New York.
The show, however, was, overall, a bit too soft on Al Capone and the other criminals.
There was also an older 1950's Untouchables tv series, which I never watched; seems it is a little similar to shows like 'Dragnet'.