All Watch Dogs Weapons Trade Investigations become available during the first act of the video game, and can be completed as soon as you find their locations, and before the third act.
Similar to other side-missions, collectibles and investigations, such as the QR Codes, in order to reveal the locations of all Weapons Trade Investigations in Watch Dogs, you have to hack the ctOS Command Centers, followed by the ctOS Towers.
After you hack the ctOS Towers in a district, you will be able to locate the Weapons Trade Investigations within the same area.
The videogame features 10 Weapons Trade Investigations, but the final mission can be played only after you complete the previous 9, and meet Tobias. In other words, on your map, you will be able to see only 9 Weapons Trade Investigations icons.
A Weapons Trade Investigation in Watch Dogs is a short activity, during which you must locate and scan a shipping crate. The crates are locked behind doors, and in order to scan them, Aiden must be close to them; therefore, first you have to unlock the doors by hacking the security systems.
For each Weapons Trade Investigation you complete in Watch Dogs, you will receive ammo and weapons.
Additionally, while exploring their locations you will be able to retrieve a series of Audio Logs.
Throughout the following guide, we explain where to find and how to complete all Weapons Trade Investigation in Watch Dogs.
Furthermore the maps below show the locations of the Weapons Trade Investigations available in the video-game.
Parker Square District
The first Weapons Trade Investigation you can complete is in Parker Square. The icon appears in the southern section of the district, as you can see on the map below. When you get close to its location, go around the building and notice the garage banner.
Hack the camera near the garage sign, and then the one across the street.
Next, unlock the switch console on the roof of the yellow building, and go back to Aiden. Return to the garage and open the door.
Take the Audio File: Undercover 01 from the table on the right, then scan the illegal weapon cache, and pick up the frag grenades.
The Wards District
The Wards District also includes a Weapons Trade Investigation. After you unlock the ctOS Towers, check your map and you will find the icon in the northern area of the district, as shown below.
The switch console you have to unlock is on top of a brown building, near another garage sign. You can unlock it while on the ground, without having to use any cameras.
Return to Jays Garage after you unlock the console, and scan the cache, then pick up the frag grenades and the Audio File: Undercover 02 near the white desk.
The Loop District
Being a larger district, The Loop features three Weapons Trade Investigations. The first one on the map below can be observed on the western island, the second in the southern area, and the third in the northern area.
The Loop District Weapons Trade Investigation 1
After you get close to the door you have to open, head east back to the main street and look for a camera in the corner of a grey building (left side while facing the street).
Use it to unlock the switch console across the alley, on the wall of the red building. Return to the garage, and pick up Audio File: Undercover 04, scan the weapon cache, and pick up the equipment.
The Loop District Weapons Trade Investigation 2
The second Weapons Trade Investigation in The Loop, as marked on the map below, requires your presence on a back alley.
While standing near the garage door you have to unlock, look for a camera in the corner of a red building, above a sign with black and yellow stripes.
Hack the said camera, and then look up on the wall above the garage door. Near the stairs is another camera. Hack it, and unlock the switch console on the roof of the building in front of you.
Next, open the door, scan the cache and pick up Audio File: Undercover 05.
The Loop District Weapons Trade Investigation 3
To get to the third Weapons Trade Investigation in The Loop District, you have to reach an underground parking lot.
After you find the garage door, follow the white line on the ceiling and cross the parking lot to get to the switch console. Unlock it, and then retrace your steps to the garage door.
Open it to find the weapon cache and Audio File: Undercover 06 on the table.
Mad Mile District
Two additional Weapons Trade Investigations can be completed while exploring the Mad Mile District. The first one is in the central area of the district, while the second one is on the small island to the west.
Mad Mile District Weapons Trade Investigation 1
For the first Mad Mile Weapons Trade Investigation marked on the map below, after you find the garage, if you follow the white line, you will notice that it ends on a roof.
The switch console can be unlocked using a camera on one of the white buildings across the street.
After you unlock the panel return to the garage, scan the crate and take the Audio File: Undercover 07 from the table.
Mad Mile District Weapons Trade Investigation 2
The second Watch Dogs Weapons Trade Investigation in Mad Mile is fairly easy to complete. After you find the garage, go around the building looking for a yellow ladder.
Climb the ladder, and then use the ramp on the roof to drop inside the fenced area. Unlock the console, and exit using the ladder nearby. Go back to the garage and scan the cache.
There is no Audio Log inside the second garage.
Brandon Docks District
The final two Weapons Trade Investigations take place in Brandon Docks District. The first one, as you can see on the map below, is located on the northern island, while the second in the western side of the district.
Brandon Docks District Weapons Trade Investigation 1
After you find the first garage, while facing it, turn right and go all around the building and the fence. The switch you have to find is on the ground, near a brown container.
You dont need any cameras to open it.
Inside the garage you will find the weapon cache, and some jam coms. Again, there is no audio log available in this investigation.
Brandon Docks District Weapons Trade Investigation 2
The second Weapons Trade Investigation in Brandon Docks starts in a back alley. First identify the garage door, and then follow the white line, until it disappears on a roof.
Near you there are several stairs leading to the switch console located behind an air vent. Hack it, and return to the garage to scan the cache.
On the blue cabinet inside the same garage you will also find Audio File: Undercover 07.
Final Weapons Mission
The final Weapons Trade Investigation mission in Watch Dogs becomes available only after you meet Tobias, because he will call Aiden and inform him about the underground organization you need to disable.
The final mission is based on combat; therefore, there are multiple ways to complete it. Your goal is to defeat three waves of enemies so make sure you restock on ammo and buy frag grenades, because in the final wave you must kill multiple enforcers.
Once you complete it, you will earn the corresponding rewards and unlock Saturday Night Special achievement/trophy.