
Quoting
Mr. Knowitall
I don't believe that is what happened, and obviously neither does the officer, but let's go with that. Let's say the friend complains to the police, "I used the money I stole to buy items that I left with my friend, and didn't bother to take until you made him give back the money that I stole, and now he says he sold them to somebody else to pay back the money that I stole." What do you imagine that the police would do?
That aside, the point is, you have made a compelling case that your son's bedroom is brimming with high-value stuff that he can sell, and you have claimed to routinely pay him thousands of dollars to perform chores, so he has ample opportunity to raise $700. If he is truly afraid to sell the stuff that he supposedly sold to his friend, he has a computer that he can sell.