Aiden Pearce may skirt some moral gray areas, but he's still a net good for the city of Chicago. While others might turn a blind eye to the plight of those ensnared by human trafficking, Aiden says no sir, not in my city. Here's a guide to the human trafficking missions, though keep in mind they won't unlock until after you complete Act 2 "A Risky Bid."
Before You Begin
You're going to be putting some high mileage on your vehicles for these missions. Each one requires you to visit a district, and ultimately to trek all the way across the map. it helps if you've unlocked the ctOS towers first, so you can use the Fast Travel option. You'll ultimately need to track down 10 buyers and 10 briefcases, and each mission will consist of both parts.
Darius Peaston - Mad Mile: Peaston will be northeast of the Mad Mile, chatting away on his cell phone. He'll be next to some garden planters. Hack his phone and the briefcase will be revealed.
Briefcase: Parker Square: Check the east side of Parker Square to the north of the baseball stadium. Just hack the intrusion box and scan the briefcase.
Carl Breenwood - Mad Mile: Carl will be in the ctOS Control Center of the Mad Mile. Hack into his phone and you'll hear some colorful language.
Briefcase - Brandon Docks: Check the northern island on the Brandon Docks. Just hack the intrusion box and scan it.
Joshua Kramer - Brandon Docks: Look at the southern shore of the most northern island. Look for him at the Boat Yard Storage.
Briefcase - The Loop: Look on the south end of the The Loop.
Adolpho C. Peccorino - The Loop: Find Adolpho near the pool at Ocean Tower.
Briefcase - The Wards: Right to the east of Iraq's compound, you'll find the case in the Wards.
Francis T. Barrthes - The Wards: Francis will be on the northwest side of Iraq's compound. He'll be chatting on the phone in a construction site.
Briefcase - Mad Mile: Near Molar's Grill, on the north end of Mad Mile, you'll find the briefcast.
Martin Graften - The Loop: Martin will be on the west island of The Loop, on the plaza near the south of Western Station.
Briefcase - Mad Mile: On the east side of Mad Mile, roughly a block west of the fast travel point.
david R. Treaklesen - Brandon Docks: Find a man alone near the water on the east end of Brandon Docks. That will be David.
Briefcase - The Loop: Between The Loop and Parker Square, there is an island on the main area. There is a case nearby, so scan that as well as hacking the intrusion box.
Paul Benedict Henfield - Parker Square: Find the baseball stadium and head southeast, then find Henfield near the docks north of the chess board.
Briefcase - Parker Square: Head to the Owl Motel, your first hideout. The briefcase will be just behind there.
Anton Chenkov - Parker Square: He's at the Botanical Gardens, surrounded by lots of other civilians.
Briefcase - The Wards: This box will be in the northeast area of The Wards, just outside a row of apartments.
Gregory Foydalem - Pawnee: Gregory will be in the Pawnee cemetary.
Briefcase - Brandon Docks: The final case will be in the Tidis Warehouse lockup.
Go to Joseph Demarco's place and hack the intrusion box. You'll have to face a simple hacking puzzle to gain access. Once inside, hack the cop's cell to trigger the next part of the mission.
Out of Business
Run to a vehicle, and try to find one that can take a beating. Then, bring up your map and mark a spot on Demarco's route, somewhere that will allow you to head him off. Make sure that it's a cross-street, though, because driving past his route to get out ahead of him will alert his convoy.
Park your car as a blocker, and then throw some IEDs on the road. Once the convoy is in range, blow one of them and the rest will follow. That will either kill Demarco, or the vast majority of his escorts. If he actually lives through the attack, use your assault rifle to take out his tires. If even that doesn't work, get back in your car and chase him down.
After you've finished taking him out, cops will be hot on your tail. Get away however you'd like, and you'll unlock the Revoking Client Privileges achievement/trophy.