The cat that played "Kitty" was diagnosed with a serious kidney condition. Rather than replace the cat, it was decided to write the illness into the story. The real cat died shortly after his final episode was filmed.
The production team has said that the characters wear colors that either complement or contrast with Brenda's outfit in each scene. Those that complement her colors are on her side or will be helpful to the investigation. Those that contrast are her opposition and/or the guilty party.
Kyra Sedgwick had doubts about taking the role, because it meant being away from her family for a few months. Knowing it was a great opportunity, her husband Kevin Bacon agreed not to work much, and stay home with their children (as Sedgwick had done many times).
Each season of this show had a theme on which its episodes were based. For season one, the theme is a woman in a man's world. Season two is about partnerships. Season three is family. Season four is described by James Duff as a meditation on power in its many forms - natural and human. The theme for season five is change, while season six seems to deal with adjustment.
In December 2010, Kyra Sedgwick announced that the show would end after season seven. TNT made a statement confirming it, implying that it was mostly Sedgwick's decision with her power as a producer. A few weeks later, it was announced that the show would have a spin-off, once season seven was over, revealing the idea that most of the cast and crew were willing to produce more stories for the characters.
It appears that among Lieutenant Provenza's four or more ex-wives, there was a Heather, a Liz (who corrected his grammar), and a Sharon (who always had to be right). His second wife and fourth wife are actually the same woman.