The Law & Order format is taken to the West Coast, where the glitz, glamor, and guilt of Los Angeles is brought into the spotlight.
True, the stories weren't in the same league as the other L&O franchises, but the show was new, character development was being done, and the writers were looking for that soap opera "hook" the other L&Os have. And the show was badly mismanaged - I mean, really, kill off a character and then run new shows featuring him?
The cast changes were also badly done, as was some of the casting itself. Alfred Molina as ADA, yes; as a detective (with a totally unbelievable reason for the change), no. Terrance Howard's character was made to look more inept than capable. And Alana De La Garza's character's relocation to L.A. was only slightly more believable than Molina's, but could have worked. The best casting was the original detective team ( a definite yin for yang developing from Episode 1), their boss, who was later re-charactered as a closeted lesbian (this should have been done either right from the get-go or somewhere in the second or third season), and Peter Coyote as the politically-ambitious DA.
To sum it up - I think the series could have been saved if it wasn't so badly mismanaged as to make me wonder if it was f***ed up by design.