Franz began his acting career at Chicago's
Organic Theater Company. Although he has in the past performed Shakespeare, his physical appearance led to his being typecast early in his career as a cop. (By Franz's own count, the character of Andy Sipowicz was his 28th role as a police officer.) He also guest starred in shows such as
The A-Team and
Hunter. Other major roles were on the television series
Hill Street Blues in which he played two characters over the run of the show. Franz first played the role of the corrupt Detective Sal Benedetto in the 1982–1983 season. Benedetto eventually commits suicide when a large-scale scam he was running fails. Franz returned to the series in 1985 as main character Lt. Norman Buntz, remaining until the show's end in 1987. He also starred in the short-lived
Beverly Hills Buntz as the same character. During the late 1970s and early 1980s, Franz worked regularly with directors
Brian De Palma and
Robert Altman. He appeared in three of Altman's films from this period, and five of De Palma's. In addition, he appeared as airport police captain Carmine Lorenzo in the 1990 film
Die Hard 2. His final film role to date was as Nathaniel Messinger in the 1998 film
City of Angels. s Franz went on to win four
Emmy Awards for his portrayal of
Andy Sipowicz on
NYPD Blue from 1993 to 2005. The character of Sipowicz was ranked No. 23 on
Bravo's 100 Greatest TV Characters list. In 1994, while still on NYPD Blue, Franz made a cameo voice appearance as himself in
The Simpsons episode "
Homer Badman", in which
Homer is accused of sexually harassing a babysitter and the case becomes
tabloid fodder, generating an exploitative television movie,
Homer S.: Portrait of an Ass-Grabber, in which Franz portrays Homer. Franz also voiced Captain Klegghorn, the commanding officer and head of the
Anaheim Police Department on the Disney cartoon
Mighty Ducks: The Animated Series, which ran from September 1996 to January 1997. In 2000, Franz starred as Earl, an abusive husband, in the
Dixie Chicks' music video "
Goodbye Earl". The next year he competed on the May 11 celebrity edition of the hit television game show
Who Wants to Be a Millionaire, winning $250,000 for his charity, the National Colorectal Cancer Research Alliance. As a commercial spokesman for
Nextel in the early 2000s, Franz appeared as a caricature of himself in commercials, "refusing" to do the commercials, saying they were not something he did.
Post-NYPD Blue After the end of the show in 2005, Franz retired from acting to focus on his private life. He mentioned in a 2015 interview with the
New York Post that he would be interested in returning to acting if given the right opportunity. He and his wife spend their summers in their lake home in Northern Idaho. He spoke of wartime experiences and postwar trauma of veterans at a
Memorial Day concert in 2012 (speaking in the first person, although it was not his own story). He and his former
NYPD Blue co-star,
Jimmy Smits, made a surprise appearance at the
2016 Primetime Emmy Awards, presenting the award for
Outstanding Drama Series to
Game of Thrones. ==Personal life==