To be safe, max out Dexterity in the focus upgrades, as I tried numerous times with no success with one point invested in it. After you have Dexterity maxed out just find a lock that needs picking and find someone weighed down by their coin purse. The rest is cake.
As of this morning I can confirm that you need Dexterity maxed out to net this trophy, as it changes the lock pick minigame when focus is active.