Due Process is *very* similar in setup as The Magician achievement and can be done the same exact way, but Due Process is a little bit interesting...
You must incapacitate a suspect with a C2 charge, which sounds simple enough but is tricky due to Ready or Not's health system.
Simply put, suspects will not get incapacitated by C2 charges without being hurt because of their health point values.
Enough preface, let's actually do this.

You can bring pretty much anything but you will need these items in specific...
 ● A 9mm handgun with JHP ammo.
 ● A single C2 charge.
 ● 1-3 flashbangs just to be safe.
 ● And a mirror gun.

This is possible on every mission but I find it is easiest to do on 23 Megabytes A Second (Streamer).
If you are doing this solo then use your commands menu and use the "MOVE TO" command to tell your AI teammates to wait in spawn so they don't interfere with your achievement quest.

Now, facing the apartment complex, go up the stairs to the right and go to the first door you see.
If the door is closed, use the mirror gun and check for any suspects, if you see one then open the door and throw a flash from behind cover and move in and yell at the dazed suspect.
If the door is open, use a flashbang from behind cover and yell for compliance on any dazed suspects.


You can shoot anyone in the room besides the civilians, you only need one single suspect.
Now that you have your achievement slave to do your bidding with, DO NOT TIE HIM.
Bring out your pistol and shoot your suspect in the butt or anywhere but the arms or legs to not cause arterial bleeding and kill him.
I recommend the pistol because you're less likely to kill your suspect with a single 9mm JHP round.

Now, with your untied suspect who you just hurt a little, use your command menu and get him to start moving within the doorframe/toward you, ideally as close to the door itself.

With your suspect as close to the door as possible, shut it behind him and then put a C2 charge on the door and blow that sh#t up.

Your suspect should be unconscious and it will appear as though they are dead, they are playing possum so when you tie them up your player character will tell TOC that you have a suspect who is alive and breathing.
This should unlock The Magician if you do not have it already and hopefully should unlock Due Process as well.

This achievement is kind of tricky and buggy so if you do not unlock it immediately, that's okay just repeat the process to the letter and you should get the achievement.

If you have any questions then feel free to leave a comment.
Have a good day!