open packages

What is the name of your state? VirginiawyM

12 year old went into a Target and opened 2 cd's and 1 dvd packages. No items were taken out of the package. Was stopped at the door and taken to security office. Purse was checked. No "stolen" items on her person/purse. Was let go with promise to pay for items. police were never called.
i go in to pay for the items, one week later, and there is a half of bag full of empty packages totaling $89.00 (at the time was told the total would be $50.00).
Store claimes that i have to pay for all items and that they must keep the items as evidence.
Any truth to any/part of this?

[judg4]

No items were found on the child? Why are you then agreeing to pay? It is not great to open the package but not necessarily illegal either.