The problem was that it carried on until another season when...
1. The show wasn't picked up for 26 episodes, it was 13. What would have happened if it were canceled before an ending?
2. It was just bad! The two lead cops are awesome, but all the other characters just got on your nerves and the political crap seemed useless. So everyone stuck around for the 13 episodes thinking we would get answers and then... nothing. If the show was better written or planned it would have been OK to carry over for another season.
Season 3 only has ten episodes and will be a stand alone mystery, so no / less filler, so that's good.