DH is being robbed silly at work - over 20 TVs were taken in one hit last month which is the biggest hit yet but hundreds, near thousands of pounds worth of inventory is going missing every month. It's definitely staff due to access restrictions. Unfortunately three different departments all have access to where these items were, the managers of these departments have all been in their roles for years and he doesn't imagine it'd be them, more likely a member of the extensive teams, but he's concerned to go to them to say to keep an eye on their staff incase it is them and he's given away that he knows. He wants to try and catch them to make sure they are fired and hopefully charged rather than they secretly get wind and just stop stealing and remain employed here, but can't afford this much loss whilst trying to gather evidence. Very limited budget wise to what new measures he can bring it to tackle it. What would you do?