This Seeking Tech guide will explain how you can easily get The Cooper Special trophy in Sly 3: Honor Among Thieves (2024) on PS5 and PS4.
To unlock this, you need to do the following: “As Sly, pickpocket 5 pieces of loot (excluding coins) without being detected.”
Use the following video as a reference:
If you turn left from the safe house of the first episode, you should find an enemy. If this enemy has a shiny back pocket, the you should steal the loot from him and then head back to the safe house.
Avoid attacking him or you will be detected.
The same enemy should respawn with a new back pocket.
The trophy should unlock when you steal the fifth loot without getting detected.