I'm used to the idea of a detective series being based around a particular thing, such as mathematics (Numb3rs), game theory (Liar Game), science (Galileo), conjuring tricks (Jonathan Creek) or what have you. This detective series is based around the art world and clues leading to the criminal are found in works of art or culture.
It's an interesting idea, but it never really works. The stories seemed quite dry and unexciting. It's hard to say exactly where the show went wrong. It doesn't help that the two main roles were fairly predictable: an eccentric amateur sleuth and a career detective. At first they don't get on but after a while, etc etc. Also, the crimes didn't seem very devious, and were quite ordinary except for some references to high art thrown in.
Perhaps the most notable thing about this detective series was that none of the main characters were under 30. That made a nice change, but it wasn't enough to save a pretty average cop show.