Compare this to Maj. Hassan, the Ft Hood, terrorist, where it took nearly four years for him to be tried and convicted and potentially decades before he is executed. This despite there being no question of his guilt. Ditto for the Boston Marathon bomber who will likely not stand trial for at least another year. There is no reason that in either the Ft. Hood shooting or the Boston Marathon bombing the terrorists should not have been more quickly tried especially when there was little doubt of their guilt.
There is a reason alright. It's the same reason divorces take more than a year rather than 2 months.
Reason: Make work for lawyers.