[Aramazon]

Whoa! Okay so I found it all out...I jumped up to Global Crisis (hardest difficulty) and I'm almost used to the break ins now. Essentially you NEED to hide behind things, and jump for cover, and use grenades. I kind of like it. It's a lot more exciting since I had to sometimes give up and just escape with what I'd gotten so far.

Couple things I've noticed...
1) Hiding is very much awesome, any baddie is easy prey when he's got his back to you. you can duck behind most furniture and they won't see you. As for disguises, they recognize you pretty easy head on, but as they don't get too close to you and you aren't facing them you should be fine.
2) Setting grenade traps is a must for when you are fleeing.
3) Any time a group is alert to your presence, it's a much better idea to take a trip to another town, and then come back again before you actually break in. Alertness actually affects guard speed. On Global Crisis, it makes it near impossible.
4) Whenever you have a shot at someone, you'll notice a cross-hair over your image in the top left corner. When that cross-hair is solid white, you have a sure hit...if it is gray, you have a chance at missing, a really good one. You'll notice that in most cases, when you first spot a baddie, the cross-hair fades into the solid white, this is to show the effects of taking proper aim.
5) Use the Home, End, Page Up, and Page Down keys to jump diagonally. Jump...a lot!

Anyways, that's what I've found on Global Crisis difficulty when it comes to break ins.

As for figuring out who the MASTERMIND Is...
Some things to keep in mind on Global Crisis difficulty
1) The name you search in the computer will only bring up results if you are using a computer of the same organization as the name.
2) The first step should be writing down all the names you encounter in files...and then figuring out which organization the mastermind is from...

Here's how I did it. I had gotten all of the other criminals figured out, and I had just left the photographer unarrested so I could keep stealing the photos and give myself more time. Anyways, when I was solving the cryptograms....which are very important, they give more info when you are in the solving screen than what you save in your records.

What you'll find is they'll say things like, "From Mercenaries High Command," or "Death Squad might also be assisting."

Anyways, each "might also be assisting" is actually a guaranteed member from that group. What I realized as I was trying to figure out which organization the master mind was from, is that I had seen the message "Death Squad might also be assisting," but none of the criminals belonged to the Death Squad...so hence, the mastermind had to be from the Death Squad. I broke into their base, checked the computer for the name (which can also be narrowed down by looking at all your extra clues, the masterminds leave no clues, so any clues with names associated, you can ignore those when trying names) and sure enough Jaime Garcia came up with a picture(you can check the manual, it has a picture of each mastermind, and they DO match up)and location and position...so now I knew that Jamie Garcia was the Death Squad mastermind in Kingston.

Then I just needed to break in and at the same time crack the computers one last time to type his name in and get his Role: Mastermind. Otherwise no arrest. Sounds easy right? Wrong, The mastermind's guards on Global Crisis are Satan incarnate compared to all the other guards...on anything other than no alert status, I'd say they're impossible...even so it took me 1 and a half hours to finally succeed. They basically shoot fast enough that they'll almost always get the first shot on you, and sometimes so rapidly that you can't even fight back. They don't hesitate before stepping through a door...they use grenades a lot, they will actually just crawl from room to room so you don't pick them up on your motion sensor, plus they recover from stunning WAY fast.

Anyways, I ended up winning by gassing a bigger room which took out quite a few of the guards, then I ran around and use booby traps to take out the other guys chasing me, I got the computer code, nabbed the mastermind, and ran out as fast as I could still leaving booby traps every door...I had 3 shots and almost got taken down on my way out...needless to say, that was my most satisfying arrest ever!