What I like about this show is that despite being dark and gruesome at times it is still quite humane, dealing with damaged people with compassion and understanding. In most other cop shows whenever there's a climactic shootout and the hero kills the bad guy it's portrayed as heroic or cool but in CM the antagonists only get killed if everything else fails and it's always seen as tragic or unfortunate; a mentally ill person gunned down by the police is not exactly a shining moment for anyone.
Another thing that distinguishes CM from other shows is that it is interested in the victims and their families. They are not just interchangeable pieces in a puzzle but are instead given agency in the story. The victims aren't just random people - though they tend to be women (mainly due to women being a favorite target for psychopaths in reality) - they tend to show intelligence and tenacity and the writers actually seem to care about them.
It's still just a procedural - and at least two seasons past its prime - but I think the showrunner, Ed Bernero, managed to inject some humanity and good characterization into an otherwise stale format with Criminal Minds.