The reason this fine show was canceled was due to much of the public. Most people were unable to properly digest the great substance of this show. There is an extreme difference in reading a book of substance such as "In Cold Blood", by Truman Capote, and reading a frivolous, coffee table book such as "Sex" by Madonna. Likewise, there is a difference between watching a program like "Homicide" and watching a program like "The A-Team". The show was so deep, people didn't watch.
The characters were outstanding. It's always good to watch excellent drama in which characters have strengths and weaknesses. Their weaknesses were were emphasized greatly to show realism. Naturally, the stories were great.
Another thing I miss was the crossover between "Homicide" and "Law and Order". These shows retained their individual styles while bringing the characters together so nicely.
It's too bad that it's gone.