Dann Florek left the original "Law & Order" series after three seasons because NBC, under the direction of then-West Coast president Don Ohlmeyer, wanted to bring more female characters to the show. This led to the decision to write off Florek's character, Captain Donald Cragen, along with Richard Brooks' character. The network's motivation was to avoid cancellation by increasing female representation. Despite creator Dick Wolf's objections, the firings went ahead, and Florek later said he didn't appreciate how quietly it was handled. However, Florek and Wolf maintained a good relationship, and Florek eventually returned to the franchise in "Law & Order: Special Victims Unit" (SVU), where he played Cragen for 15 seasons until the character retired to travel, marking an honorable and positive exit.

In summary:

• Florek was fired from the original "Law & Order" due to NBC's demand for more female characters.
• He was one of two male actors dismissed to make this shift.
• Later, he returned to play his character in "Law & Order: SVU" for many years.
• In SVU, his character retired to travel, concluding his role on a positive note.