I had a brain fart. Of course it is the Palais de Justice. I'd even visited the Ile de la Cite, specifically the Sainte-Chapelle and Notre Dame.
Thanks for the information. So, basically, this is a local courthouse for Paris, and not a national courts building. BTW, as I'm sure you know, a lot of municipal and county courts here in the States are housed in towers even less aesthetically pleasing, for instance, here is the courts building in my hometown of Detroit (to the left):
IMG_1822 A by
markh0421, on Flickr
So this isn't horrible, but they could have done better with the massing.