There is a big chance of problem with swift or military trial as well. Public does not get to know the real truth. And there may not be any any possibility to know the whole truth.
Only way to get real justice is open trials. With complete protection to those who conduct these trials.
It is a separate case, but if the judge who convicted Salman Taseer murderer had to flee the country then it is the fault of security forces not to be able to protect this judge.