Adding an Item to another Case (Item belonging to multiple Cases)
From the Case View \ Items Tab, click any number of item(s) and choose Add to Case from the Actions menu to add the item(s) you’ve chosen to a particular Case.
The Add Items to Case screen will then be shown.
Enter a Required Case Number in the Case Number field. As soon as you begin typing a Case number, selections will appear to choose from. Pick 1 and click Ok.
Your Item(s) will then be added to the Case you chose.