The following is an excerpt from a conversation between the store manager of Wholesome Grocery Stores, Kara Dahl, and Lynn Shutes, president of Wholesome Grocery Stores:

Lynn: Kara, I'm concerned about this new scanning system

Kara: What's the problem?

Lynn: Well, how do we know the clerks are ringing up all the merchandise?

Kara: That's one of the strong points about the system. The scanner automatically rings up each item, based upon its bar code. We update the prices daily, so we're sure that the scale is rung up for the right price.

Lynn: That's not my concern. What keeps a clerk from pretending to scan items and then simply not charging his friends? If his friends were buying 10-15 items, it would be easy for the clerk to pass through several items with his finger over the bar code or just pass the merchandise through the scanner with the wrong side showing. It would look normal for anyone observing. In the old days, we at least could hear the cash register ringing up each scale.

Kara: I see your point

Suggest ways that Wholesome Grocery Stores could prevent or detect the theft of merchandise as described.