I think it is the same person. As for the first mug shot it was probably taken by the arresting Deputy at the local Sheriff's Office or substation. Like the Police department I work for I bet the camera is a piece of crap. When I take a mug shot of someone it is a very quick process for our records. The results usually come out mediocre at best, but good enough. I know that once the defendant is taken to the county jail a better, clearer, more professional mug shot will be taken. This is the one that usually is released to the public. However due to the seriousness of the incident the media wanted a photo of the defendant ASAP so they opted for the mediocre one. This is my theory of course.
As for the "joker" smile in the first photo I think it is Loughner thinking to himself "oh shiz, what the freak did I just do." It is likely the
original photo was taken only hours after he just committed a mass murder. Of course his facial expressions are going to appear different then the
On to photo two. I am pretty sure this is the mugshot taken by the US Marshall's. This was probably taken a couple days after the first one. Perhaps
the camera and lighting was better where the second photo was taken. I am almost 100% sure the two photos were not taken in the same building. Since
the photo was taken sometime after the first photo I would assume it gave the defendant sometime to calm down. If you can calm down after committing a
mass murder. Perhaps that is why the second photo does not appear to be as "menacing" as the first.
I highly doubt there is any conspiracy here. Of course this is my opinion and I could be wrong.