Idris Elba is Luther.
In the past week, folks here and on Facebook have been either asking about the show or commenting on the show.
They are about to air season 3 which will only have 4 episodes (boooo) just as season 2 had.
If you have Netfix, you can catch the first couple seasons from the beginning. I hear it is On Demand with some cable companies.
This is a British cop show where the characters talk in strong accents. In order to understand what's going on, you must start from the first episode and work your way through.
Here's the link from BBC America so you can read what they're saying about the show.