1 Question, ''How do I keep an employee from stealing from me?'' Whats your answer?

First person who suggests a solution to this problem, that I like, wins the bid. Should be easy money, for the right person. **Question**: How do I keep a new employee who shops for me, from stealing from me? **Background:** I can no longer make purchases myself. I need to hire someone to make purchases for me. I won't hand them cash, or credit card to make these purchases, I was thinking store gift card. Say I gave them a $100 walmart gift card to purchase $100 worth of stuff for me. Now say I wanted to pay them like $30 for their time, but they'd only get the $30 after they did the work for me. Whats to keep this newly hired employee from taking the $100 gift card and run? Or to buy whatever they want with the gift card, and run. Or sell my giftcard on ebay? I think I know how to screen good people from bad, but given the right circumstances, couldn't anyone I hire steal from me? What I'm giving them will always be worth more then what I'm paying them for their work. They work alone, no one is with them. Also, sometimes I need them to go to more then one store, or make larger purchases then $100. Say I need them to go to Rite Aid to get me $50 worth of stuff, I need them to go to Office Depot and buy $250 worth of stuff, and go to Walmart and buy $300 worth of stuff. Do I just hand them 3 gift cards ($50 RA, $250 OD, and $300 WM), and just cross my fingers and hope they do the right thing? Because they are an employee of mine, I will have photocopied there Drivers license and Social Security card, so I will have that. But if they steal from me, what do I do, call the police? The employee has all proof, they have the stuff, the gift cards, the receipts, initially its my word against theres, and really is all I'm really going to get is a police report anyway? I don't have insurance for this type of work, so the police report doesn't aid me much, or does it? I know I can do background checks, but how do you know the person your hiring to go to work for you isn't moving to Alaska next week, they just failed to mention that? So you give them the gift cards, and they split town, now what? I know there are shopping services, but mine is unusual, and highly competitive. I'd need someone to be working directly for me, so a service wouldn't work.